Reddit Stories - Sibling became fixated on DEMONSTRATING I was not a BIOLOGICAL RELATIVE after Father

Episode Date: November 11, 2025

#redditstories #askreddit #aita #familydrama #relationships #identitycrisis #genetics #fathersecretsSummary: Sibling became fixated on DEMONSTRATING I was not a BIOLOGICAL RELATIVE after Father. Their relentless pursuit of proof strained our relationship and caused deep emotional turmoil. I struggled to navigate this revelation and redefine my sense of family and belonging.Tags: redditstories, askreddit, reddit, aita, tifu, familydrama, relationships, identitycrisis, genetics, fathersecrets, siblingrivalry, familysecrets, emotionalstress, familybond, belonging, personalidentity, naturevsnurture, paternitytest, familyconflict, siblingrelationshipsBecome a supporter of this podcast: https://www.spreaker.com/podcast/reddit-stories--6237355/support.

I hope you enjoy this story. Sibling became fixated on demonstrating I was not a biological relative after father brought up revising his last wishes. Thus she attempted to obstruct my genetic examination by entering her pals spit under my identity. So here's the background. I'm 28, my sister Fiona is 31. We've always had a decent relationship, not super close, but we get along fine at family gatherings, text occasionally, normal sibling stuff. Our dad is pretty well off, owns a successful contracting business that he built from nothing. Mom passed away eight years ago from cancer.

About six months ago, dad started talking about updating his will. Nothing dramatic, just mentioned he wanted to make sure everything was in order, maybe set up some trusts, that kind of thing. Pretty normal for someone in their early 60s who's thinking about retirement and legacy planning. Fiona and I are his only kids, so we'd be splitting his assets. Ever since then, Fiona has been acting completely different toward me. And I mean completely different. She went from normal sister too.

I don't even know how to describe it. Suspicious? Hostile. She keeps making these word comments about how I don't really belong in the family and how I've always been different. The first time she said something, we were at Dad's House for dinner. She was looking at old family photos on his mantle and picked up this picture of me as a baby. She stared at it for way too long, then said, you know, you really don't look like either mom or dad in this picture. I laughed it off because honestly, baby pictures are

pretty much useless for determining family resemblance. All babies look like wrinkled potatoes. But then she kept going. No, seriously, look at your nose. Look at your eyes. Where did those features even come from? She was holding the photo right up to my my face. Dad was in the kitchen and didn't hear this exchange, but I was starting to feel uncomfortable. I told her she was being weird and that plenty of kids don't look exactly like their parents. I mean, genetics is complicated, right? Sometimes you get your great-grandmother's chin or your uncle's eye shape or whatever. But Fiona just gave me this look like I was lying about something. What's really getting to me is how she started talking about me being fake around

other family members. At my cousin's birthday party last month, I overheard her telling our aunt that she's always suspected something wasn't right about me. When she saw me listening, she didn't even look embarrassed. She just shrugged and walked away. The weirdest part is how she's become obsessed with family genetics and inheritance stuff. She keeps bringing up stories about families who discovered shocking secrets through DNA testing. She sent me three different articles about people finding out they were adopted or had different fathers. She's constantly mentioning how DNA doesn't lie and how science can reveal the truth about family relationships.

Last week, she cornered me at Dad's house and straight up asked me if I'd ever wondered about my real parents. I was so shocked I didn't even know what to say. I asked her what the hell she meant by that, and she said she's just been thinking about family genetics lately and how I'm so different from everyone else in the family. I tried to talk to Dad about Fiona's behavior, but I didn't want to get too specific because frankly, it sounds insane when I try to explain it. I just said Fiona seemed stressed lately

and was saying some odd things. He said he'd noticed she'd been more intense recently but figured it was work stress. The thing that's really messing with my head is that Fiona seems completely convinced of whatever theory she has. She's not acting like someone who's just being malicious or trying to start drama. She seems genuinely convinced that there's some big secret about my parentage that everyone is hiding from her, but here's what I know for absolute certain, I am definitely dad's biological child. I have his hands, his laugh, his tendency to get angry at inanimate objects when they don't work properly. I have mom's stubborn streak and her weird double-jointed thumbs.

I look like both of them in different ways. I'm starting to wonder if Fiona is having some kind of mental health crisis. The timing with Dad's Will Update seems too coincidental to ignore. Is she so worried about inheritance that she's convinced herself I'm not really family? Is this some kind of psychological response to grief over Mom's death that's just surfacing now? I don't know what to do here. Fiona's behavior is getting more intense, not less. She started making comments about DNA testing and getting to the truth in front of Dad. He just laughs it off, but I can tell he's starting to notice that something is off with her. Any advice would be appreciated because I'm completely lost here.

Update 1, so remember how I said she was obsessed with DNA testing and family genetics? Well, she's decided to turn her obsession into a family activity. Fiona showed up at Dad's House a few days after my original post with this presentation about genealogy and family history. She had printed out articles about DNA testing, family tree research, genetic genealogy. She pitched it as this amazing bonding project where our whole extended family could participate in creating a comprehensive family tree using DNA analysis. Her presentation was actually pretty impressive. She had researched different testing companies, compared their accuracy rates, looked into

their databases for genealogical research. She talked about how we could connect with distant relatives. discover family migration patterns, maybe even solve some family mysteries about our great-great-grandparents. Dad was immediately interested. He loves anything related to family history and has always wanted to trace our lineage back further. Fiona had done her homework and knew exactly how to appeal to his interests. She talked about how we might discover connections to historical figures or find out about family members who immigrated from Europe. But here's the thing that made my skin crawl. Fiona insisted that everyone had to participate for the project to work properly.

She said the DNA comparisons would only be meaningful if we had samples from multiple generations and family branches. She specifically emphasized how important it was that both Dad and I participate, since we're the direct male lineage. She made it sound so reasonable and scientific. She kept talking about how DNA testing has become so advanced that it can reveal incredible details about family relationships and genetic inheritance patterns. She mentioned how some families have discovered they had famous ancestors or connected with relatives they never knew existed.

The really manipulative part was how she framed it as a gift for dad. She said she wanted to create this beautiful family tree as a surprise for his upcoming birthday, complete with DNA analysis and historical research. She made it seem like this thoughtful, loving gesture from a daughter who wanted to honor her father's interest in family history. Dad ate it up completely. He started talking about how mom would have loved this project and how amazing it would be to finally get answers about some of the gaps in our family knowledge.

He immediately agreed to participate and started calling other relatives to get them involved. Fiona was so smooth about it. She handled all the logistics, ordered all the test kits, coordinated with family members. She made herself the project manager and insisted on collecting all the samples personally to make sure they were handled properly and sent to the lab correctly. Within a week, she had gotten commitments from dad, me, our two aunts,

three cousins, and dad's elderly uncle. Everyone was excited about the project. Our aunt even started digging through old photo albums and documents to contribute to the research. But I know what this is really about. Fiona isn't interested in genealogy or family history. She's trying to prove that I'm not dad's biological child. She's convinced that when all the DNA results come back, mine will somehow show that I'm not genetically related to the rest of the family. Instead of making direct accusations or confronting me privately, she's created this scheme that makes her look like the thoughtful,

organized daughter while putting me in a position where I can't refuse to participate without looking suspicious. If I object to the DNA testing, it will seem like I have something to hide. If I point out that Fiona's real motivation is to prove I'm adopted, I'll sound paranoid and defensive. She's backed me into a corner where my only option is to go along with her plan and hope that the DNA results shut down her adoption theory once and for all. The worst part is watching Dad get excited about this project. He's been calling me every few days to share new information Fiona found about genealogy research

or to talk about potential family connections we might discover. He has no idea that his daughter is using his interest in family history to try to prove that his son is not actually his son. I keep telling myself that this will backfire spectacularly when the DNA results confirm that I'm definitely dad's child. Fiona will have to face the fact that her adoption theory is completely wrong, and hopefully she'll drop this whole obsession. Update 2, the DNA test kits arrived at Fiona's apartment since she was coordinating everything. She texted our family group chat that she'd received all the test kits and would be distributing them so everyone could submit their samples. She said she wanted to collect them all at once

to send to the lab as a batch to make sure they were processed together. I was supposed to meet her yesterday to pick up my kit, but I had to cancel because of a work emergency. I texted her that I'd come by today instead to get it. She said that was fine and that she'd leave it with her roommate if she wasn't home. So I drove over to Fiona's place this afternoon. Her roommate let me in and said Fiona was running errands but had left my test kit on the kitchen counter. There were two test kits on the kitchen counter, so I grabbed one and was about to leave when I noticed that the box had already been opened. That seemed weird because these kits are supposed to be sealed until you're ready to use them. I opened the box to check if everything was inside, and that's when I saw that the

saliva collection tube already had someone spit in it. I stared at this tube for probably five minutes trying to make sense of what I was seeing. The collection tube was supposed to be empty when I received it. I was supposed to spit into it myself, seal it, and then send it to the lab. But there was already saliva in the tube. My first thought was that Fiona had accidentally given me someone else's completed kit. Maybe she'd mixed up the boxes and given me a relative sample by mistake. But then I looked at the paperwork in the box, and it clearly had my name on all the forms. That's when it hit me. Fiona was planning to submit someone else's DNA sample under my name. I immediately called her and asked what the hell was going on with my test kit. She acted confused

and asked what I meant. I told her that the collection tube already had saliva in it and the form had my name filled in it, and there was this long silence on the phone. Then she said, started laughing and said it was just a joke. She said she was testing me to see if I'd notice, and she was impressed that I caught it. She claimed she had filled the tube with her own saliva as a prank and that she had my actual test kit ready for me. I told her that wasn't funny and that tampering with DNA samples was not a joke. She kept insisting it was harmless and that she was just messing around. When I got home, I started thinking about it again. I called her back and demanded to know whose DNA was actually in the collection tube.

She tried to brush me off again, but I kept pushing. Finally, she admitted that she had asked her friend Isabel to provide the sample. Isabel is Fiona's co-worker, someone I've met maybe twice at Fiona's parties. She's not related to our family in any way. If Isabel's DNA was submitted under my name, the results would show no genetic relationship to dad or any of our other relatives. I asked Fiona point-blank why she would do this. Why would she try to submit someone else's DNA under my name? What was she hoping to accomplish? That's when she finally stopped pretending this was a joke. She said she needed to know the truth about my parentage

and that she was protecting dad's interests. She said if I was really dad's son, I shouldn't be afraid of taking the test properly, but if I had something to hide, this would reveal it. Her logic no sense. She seemed to think that by submitting fake DNA under my name, she would somehow expose me as a fraud. Like, if the fake results showed I wasn't related to the family, that would prove her adoption theory was correct. I tried to explain how insane this was. I pointed out that submitting someone else's DNA would only prove that Isabel isn't related to our family, which we already knew. It wouldn't prove anything about my actual genetic relationship to dad. But Fiona wasn't listening to logic.

She kept insisting that I was hiding something and that my reaction to her plan proved I was scared of the truth. She said if I was really dad's biological son, should have no problem taking the DNA test legitimately. I told her I absolutely would take the test legitimately, but that I wanted a completely new kit that she had never touched. I said I would order my own test directly from the lab and submit it myself to make sure there was no tampering.

Fiona got angry and accused me of being paranoid and ruining the family genealogy project. She said everyone was excited about the research and that I was destroying it with my suspicious behavior. I pointed out that she was the one acting suspicious by trying to submit fake DNA samples, but she just kept deflecting and saying I was overreacting to what she claimed was a harmless prank. The conversation ended with her hanging up on me after I said I was going to tell dad what she had tried to do. She immediately texted me begging me not to involve dad and promising she wouldn't interfere with my actual DNA sample if I just let this go. I'm not letting this go. Fiona literally tried to commit fraud by submitting someone else's DNA under my name. This goes

way beyond weird suspicions about my parentage. I ordered my own DNA test kit directly from the lab today. I'll submit my actual sample and get legitimate results that will prove I'm dad's son. This is so much worse than I thought. Update 3, the DNA results came back and surprise surprise. I am definitely Dad's biological child. But Fiona's response to this proof has been absolutely unhinged and I'm starting to worry about her mental state. I got my results first because I had ordered my own kit directly from the lab

while Fiona was still coordinating the family batch testing. My results showed exactly what I expected. 50% genetic match with dad, clear genetic relationships with our aunts and cousins, European ancestry matching our known family background. Everything lined up perfectly with what you'd expect from someone who is definitely part of this family. I was honestly relieved to have scientific confirmation of something I'd never doubted. I thought this would finally end Fiona's bizarre adoption conspiracy and we could move on from this whole mess. I decided to show Fiona the results before sharing them with the rest of the family.

I figured this would give her a chance to acknowledge she was wrong and maybe apologize for all the accusations and sabotage attempts. That was a mistake. When I showed Fiona my DNA results, she stared at them for a long time without saying anything. Then she started asking detailed questions about the testing process. Where did I order the kit? How did I submit the sample?

Was I sure the lab didn't mix up samples? Had anyone else handled my test kit? I explained that I had ordered the kit directly from the company's website, submitted the sample myself, and tracked the entire process to make sure there was no contamination or mix-ups. The results were definitely accurate. Fiona's response was to accuse me of tampering with the test somehow. She said there was no way these results could be legitimate because she was certain that I wasn't

dad's biological child. She insisted that I must have figured out a way to manipulate the testing process. I asked her what possible evidence she had for thinking I wasn't Dad's son, and she started listing these completely random observations. She said I hold my fork differently than Dad does. She said my laugh sounds forced when I'm around family and I've always been too eager to fit in with the family, which she thinks proves I know I don't really belong. This is completely insane reasoning. She's taking normal human behaviors and twisting them into evidence of some grand deception about my parentage.

But it gets worse. Fiona has decided that the solution is for everyone in the family to retake the DNA tests at a different lab. She says she doesn't trust the company we used and thinks we should get independent verification of the results using a different testing service. She's been calling family members individually to pitch this idea. She's telling them that DNA testing can be unreliable

and that it's important to confirm results using multiple labs. The really manipulative part is how she's framing this to Dad. She's not telling him that she thinks I'm adopted or that she tried to sabotage my original test. Instead, she's presenting herself as the careful, thorough researcher who wants to make sure our family genealogy project has the most accurate data possible. Dad thinks this sounds reasonable. He doesn't know about Fiona's adoption theory or her sabotage attempt, so to him, this just seems like Fiona being thorough about the genealogy project.

He's agreed to take another test and has encouraged other family members to participate in the expanded research. Fiona has already ordered new test kits from a different company. She's coordinating the collection process again, which makes me nervous given her previous attempt at sabotage. But this time, I'm making sure Dad is present when I submit my sample, and I'm taking photos of the sealed kit to document the chain of custody. The frustrating part is that I know these new results will just confirm what we already learned.

I will test as dad's biological child again because that's what I am. But Fiona seems convinced that a different lab will somehow produce different results that support her adoption theory. I'm starting to think Fiona has developed some kind of delusional disorder focused on my parentage. She's constructed this conspiracy theory and is now rejecting any evidence that contradicts it. When reality doesn't match her beliefs, she's deciding that reality must be wrong. I'm tempted to tell Dad everything, but I'm worried he won't believe me. Fiona's behavior seems so rational on the surface that my accusations might sound like paranoid rambling. Plus, she's been very careful not to voice her adoption theory in front of

dad directly. I think my best strategy is to go along with a second round of testing and let the results speak for themselves. When the new lab confirms that I'm Dad's biological child, Fiona will have to face the fact that multiple independent tests have reached the same conclusion. This whole situation has gone from annoying to genuinely concerning. I'm not just dealing with sibling rivalry or inheritance anxiety anymore. I think Fiona might actually be having some kind of psychological crisis that's fixated on proving I'm not part of the family. Update 4. I told Dad Everything and Fiona is completely out of my lives now. This whole situation exploded in ways I never expected and I'm honestly relieved it's over. The second round

of DNA tests came back with identical results to the first round. Shocking, I know. I am still definitely dad's biological son, still genetically related to all our relatives, still have the same ancestry markers. The results were essentially photocopies of my first test. I thought Fiona might finally accept reality when confronted with identical results from two different labs, but instead she doubled down harder than ever. She immediately started researching DNA testing accuracy rates and found some obscure studies about laboratory errors. She began insisting that both labs must have made the same mistake or that there was some kind of systematic contamination affecting my sample specifically. But the breaking point came when she started approaching

other family members with her adoption theory directly. She had kept her suspicions mostly private before, but after the second round of test results confirmed I was Dad's son, she apparently decided subtlety was no longer working. She called our cousin Mike and told him she had serious concerns about my parentage and that she thought Dad was being deceived about having a biological son. She asked Mike to help her convince Dad to demand a third round of testing at a lab that she would personally select and monitor. Mike was completely bewildered by this conversation. He called Dad immediately and told him that Fiona seemed to be having some kind of break about family genetics and was making bizarre claims about me being adopted.

Dad called me right away and asked what the hell was going on. I realized I couldn't protect Fiona from her behavior anymore. She had escalated to involving extended family and her delusions, and Dad deserved to know what his daughter had been doing. I told him everything. The months of suspicious comments and adoption hints. Her manipulation of the Family Genealogy Project to try to expose my supposed fake parentage.

Dad listened to this whole story in complete silence. When I finished, there was this long pause, and then he said, she's been trying to prove you're not my son. Why would she do that? I told him I thought it was connected to his will update and that Fiona seemed to be trying to get me removed from his inheritance. Dad got very quiet and said he needed to talk to Fiona immediately.

The confrontation with Fiona did not go well. Dad called her over to his house and asked her directly if she had been questioning my parentage and trying to prove I was adopted. Fiona initially tried to deny it, but when Dad mentioned the DNA test sabotage and her calls to family members, she realized there was no point in lying anymore. She admitted that she believed I wasn't Dad's biological son and that she had been trying to prove it for months. She said she was protecting Dad's interests and making sure his inheritance went to his real kid. She claimed she was doing this out of her.

of love and loyalty to Dad. Dad asked her what possible evidence she had for thinking I wasn't his son, and Fiona started listing the same ridiculous observations she had shared with me. She also mentioned some childhood memories that she claimed seemed inconsistent with me being his biological child. Dad told her that her evidence was completely absurd and that she had been trying to destroy her brother's relationship with his family based on nothing but paranoid speculation. He said he was ashamed of her behavior and couldn't understand how she had convinced herself to do something so cruel. Fiona broke down crying and kept insisting that she was right about me, that the DNA tests were wrong, that Dad was being fooled.

She begged him to do one more round of testing with a lab that she would personally verify and monitor. That's when Dad lost his temper. He told Fiona that she was delusional and that her obsession with proving I wasn't his son had damaged our family permanently. He said he couldn't trust her anymore and didn't want her around until she got professional help for whatever psychological issues were driving this behavior. Fiona left Dad's house that day and hasn't spoken to either of us since. She's blocked my phone number and social media accounts. She's also apparently blocked Dad because he says his calls go straight to voicemail and his texts aren't being delivered. Dad kept asking me why I hadn't told him sooner about Fiona's

behavior, and I explained that I had hoped she would come to her senses and that I didn't want to cause family drama over what seemed like temporary paranoia. But Dad said he was glad I finally told him the truth because Fiona's behavior had been escalating and might have gotten even worse if left unchecked. Dad has decided that Fiona needs professional psychological help before he'll consider having a relationship with her again. He's told her through other family members that he'll pay for therapy if she's willing to address whatever drove her to this behavior, but that he won't tolerate any first.

contact until she acknowledges that her adoption theory was delusional. As for me, I'm done with Fiona permanently. I don't care if she gets help or acknowledges she was wrong. She spent months trying to destroy my relationship with my father and remove me from my own family. She attempted fraud by trying to submit fake DNA samples under my name. She involved extended family members in her campaign against me. Dad has told me he's reconsidering a few things regarding his estate planning. He won't give me details, but I suspect Fiona's inheritance situation has changed significantly. He's mentioned that trust and loyalty are important factors in how he thinks about family legacy. I know some people might think I should forgive Fiona if she gets help and

apologizes, but I'm not interested in reconciliation. Some betrayals are too fundamental to overcome. She tried to erase me from my own family. That's not something I can move past.