AITA For Telling My Sister She Was Dating My Bio-Father?

A Redditor (24F) is struggling with the fallout after revealing to her sister (27F) that her new boyfriend is their biological father, whom she had been told to keep secret. Growing up as the result of an affair, the Redditor was introduced to her bio-father at 17 and promised to keep the secret from her sister.

But when her sister started dating him, she decided to come clean. While her sister wasn’t angry, their mother is furious, calling her a “traitor” and accusing her of breaking a trust.

Now, the Redditor is questioning whether she was wrong for revealing the truth. Read the full story below to see the full drama unfold.

‘ AITA For Telling My Sister She Was Dating My Bio-Father?’

So, my life’s turned into a bloody soap opera recently and I could use some outside opinions here. I (24F) am the product of my mom having an affair. Fortunately my dad decided to forgive my mom and keep me, and I had a pretty good upbringing.

But I don’t really look a lot like the rest of my family (I’m the only redhead, among other things) and I did ask questions of a ‘why am I the only one with -insert trait here-?’ nature growing up.

When I was 17 my mom took me out for ice cream and introduced me to my bio-father. She said that she felt I was old enough to know the truth, and explained about her affair, while also A) making me promise I wouldn’t tell my older sister (27F in the present) and B) hammering home along with my bio-father that he’d never be part of my life and didn’t want me.

It was a lot, I won’t lie, but I learned to suck it up and move on with my life. Fast forward to the present. My big sis has always gravitated towards older men (we like to joke that it’s the result of too many George Clooney movies growing up) and two months ago shared a picture of herself and her new boyfriend.

Who, to my shock, turned out to be my bio-father. I debated what to do for a couple of days, then ultimately decided she needed the truth and told her. My sister did not take it well and dumped him, but she wasn’t angry with me.

Honestly by now she’s kinda amused, says that since she banged my dad she’s my mom and has extra power to boss me around now. My mom on the other hand, is *furious*.

She says I divulged something that wasn’t my secret to share, and that I had no business telling anyone. That since bio-father isn’t related to my sister it didn’t matter if he dated my sister and it wasn’t like they were talking marriage anyway.

It’s been two month and she’s still angry, still snide, calls me a t**itor and finds excuses to make loud comments about how I can’t be trusted with anything private or important so beware.

At the time I thought I was doing the right thing, but I’ve never seen my mom this angry before, and she’s sustained that anger for 2 solid months, so I’m starting to worry. Did I actually do something really s**tty, am I the a**hole?. ​

EDIT: Wow, this got a lot more comments than I expected. I can’t answer everyone, but I do appreciate every comment and the support that I’m getting.

Two months of having your mom furious with you takes quite a toll, so it’s been really relieving seeing so many NTAs in the comments. Thank you all, I’m trying to read everyone even if I don’t reply!

Take a look at the comments from fellow users:

[Reddit User] −  NTA, she needed to know that, that’s weird and a little too close to home. Also it’s kind of messed up that your older sister was never told about this key part of her family history.
Also if your bio-father knew who she was and her relationship to you that’s really weird and creepy.

BroadElderberry −  NTA.
Your mom is taking her feelings about herself out on you.. calls me a t**itor. She’s the one who cheated on her family
I can’t be trusted with anything private or important…Says the woman who couldn’t be trusted to stay faithful to her marriage.

It’s weird and messed up that your mother wasn’t the *least* bit icked out that her daughter’s father was hooking up with her other daughter. Her feelings must be a category 4 hurricane right now.

Asantos1234 −  NTA. It’s about your life, you can tell anyone you want!

akoudagawaismywaifu −  NTA that’s creepy as hell, imagine if your sis ended up marrying or having a kid with him or something.
Your bio dad would be your brother in law, your niece would be your bio sister, and your older sister would be your step mom.

Yeah no, she needed to know about that, and you’re not an a**hole for telling her as she isn’t even mad. Your mom on the other hand shouldn’t be mad either, because does she seriously want her daughter to marry her fling???

Fleetdancer −  NTA. Your mom is deeply, deeply embarrassed by her infidelity. Rather than be a f**king adult about it and become a better person she’s put the burden of keeping her secret on your shoulders.

Your origin is not her secret, it’s your life. Next time it comes up tell her she can shut up and deal with it or you’ll be perfectly happy to start telling everyone. After all, you’re not the one who has anything to hide here.

[Reddit User] −  NTA. This guy (your bio-dad) bangs a married woman and then bangs her daughter? Your mom REALLY does not care about her own husband does she?

She really does not care that the guy who banged his wife was now banging his daughter? Holy s**t, your (non-bio) dad deserves an award for putting up with your mom.

DarkForceM05 −  NTA you did nothing wrong. You did the correct thing . You mom on the other hand is dead wrong for say you can not be trusted. She is lashing out because her secret and lies are no longer hidden.

It is great you and your sister are laughing about it now.. since you 2 are the ones that should have known that info.. How does you dad feel about it ?.

bethfromHR −  NTA. Few things are more your business than your family history.
1. It is entirely inappropriate for another person to say you need to keep secrets about yourself, and that’s exactly what this was.

2. It is just as inappropriate for a parent to divulge infidelity to their own child and then expect them to keep the secret. That is not healthy parenting, and your mother is as big an a**hole for that as for the original affair.

You are not responsible for your mother’s good name, nor do you need to hide the truth of your history in order to make her more comfortable with her own poor decisions.

Quinnshot −  NTA and also weird af because she doesn’t see anything wrong with the fact that she and your sister shared a d**k. Your mom is problematic af. I would clown her on the regular for sleeping with the same person my sister slept with.

IneffableB −  NTA. However, your bio-dad is MAJORLY the a**hole. He’s your dad and hooked up with your mom before…he knew what he was doing.

Also, your mom and sister haven’t handled it well either. Saying “I banged your dad” is an a**hole move, and your mom staying angry with you for so long is one too.

Was the Redditor in the wrong for revealing the truth about her bio-father, or did she do the right thing by telling her sister? How would you have handled a situation like this with your family? Share your thoughts in the comments below!