Is AUTHOR wrong in the post ? POST : Basically I'm facing a bit of an ethical dilemma and I'm pretty deep into this emotionally so who better to ask than the internet? At the core, my question is WIBTA if I were to tell the "baby daddy" of my ex-best friend that he is most likely not the father, and at the very least he needs to get a DNA test done to confirm it before he throws his life down the drain? Seems like an easier question, but tbh my main motivating force behind this is revenge against my best friend, so that seems....conflicting.

My best friend is in her early 20's. I'm in my 30's, and male. A bit unorthodox, but we've had a strangely open and honest, close connection since we met, the age thing never bothered either of us, so we've just gone with it. It works for us. But we are in different places of our lives obviously. She's trying to be young and free and I'm looking more to settle down. I also have things figured out a lot more and she's trying to find herself and be young and free. So she is always needing support. Sometimes financially, and I've helped her with bills before, but mostly just always being there for her, being supportive, encouraging, and helping her see herself the way I see her when she's depressed. She is not able to do a lot of these things for me; she's been surrounded by garbage people her whole life that treat her like trash so I don't think she's ever really learned how to be a good friend. But I don't need the support usually the way she does, and we've talked about it honestly with each other, and she tries, and works to be better, so it didn't seem like a big deal usually. 

Glossing over a lot of drama (cuz she always has drama), I catch feelings and fall for her. We've always been flirty since the beginning, and we've gone back and forth on the dating thing, but thru it all we've been able to talk openly and honestly with each other so we've remained best friends. She doesn't feel the same way, but has off and on had romantic feelings for me according to her and has gone back and forth on it. 

We end up having a fight (reason not too important, basically she told me she wanted to try a relationship then a week later told me she only said that to make sure I stayed her friend and so I wouldn't leave to go back on the road for work),  and she ghosts me for a couple weeks. She supposedly gets pregnant during this time with "baby daddy". The night of our fight tho, she had taken a pregnancy test cuz she was worried she was pregnant with a guy she had broken up with right before I got back and she wanted us to try. She had sex with him up to a couple days before the test was taken. 

I was suspicious from the beginning that it was really baby daddy's kid. She and I started talking again when she found out she was pregnant and then baby daddy ghosted her a week or two later cuz she wouldn't have an abortion. He was in college, came from a good family, and his parents saw her as white trash that was wrecking their sons life. I was a bit more distant when we started talking again cuz I felt like I could no longer trust her, but I felt bad for her situation and still cared a lot about her so I tried to help how I could. 

So we're getting back into things over the next couple months, getting very close again, and start looking for an apartment together. I still have the feelings, she's still back and forth, but I just want my best friend to have a safe, good home while she's pregnant since she's basically couch surfing at this point after getting evicted. 

So everything is good, I'm being crazy supportive again, we're having good times, I'm going to her doctors appointments with her, we're planning a home, baby daddy is nowhere to be found. Then as she's texting me pics of the place we are getting while I'm at work, she blows up about a flirty joke I send her. Says she doesn't want to be in a relationship with me, never will, and the apt is off the table. She said she only told me there was a chance between us to make me happy. It had taken a lot for her to regain my trust and I felt like our lives were moving in a good direction, she and I had talked a lot about how even if we weren't in a relationship she wanted me to be there as a male role model and doing all the pregnancy stuff with her had made me start getting really attached to the idea of having that kid around. And she knows I want kids. It doesnt help that im in love with her and we were planning a home. It was incredibly vulnerable territory for me emotionally, but i was trying to do the best i could so she was taken care of. All that was gone in the space of 20 minutes, for what I felt like was no reason. 

I asked her the next day what the hell happened. Her response is that baby daddy had shown back up, told her he loved her and wanted to be a family. I told her she was being an idiot. We tried to work things out for a day or two, but I was feeling incredibly hurt, incredibly betrayed (I already had massive trust issues she knew about), and she was dead set on never anything romantic and she couldn't see past my feelings for her. So she blocked me on everything and ghosted me. 

The other day I noticed the time stamp on a picture I had of her, worked some math in my head, and realized her supposed conception date was literally the day after she had taken her pregnancy test. I am almost 100% certain at this point it is not baby daddy's kid. I am feeling hurt beyond belief, I feel like I lost my best friend for not a very good reason at all, and I feel like she was just using me this whole time for financial and emotional support. She won't talk to me, won't talk about what happened with our mutual friends, and offers no explanation. So I'm feeling super used and betrayed. I know if this guy finds out its not his kid that he'll happily bail. He never wanted the kid in the first place and she and him had been done before she discovered she was pregnant. Telling him will blow up her world and cause her immeasurable grief. I want revenge, as petty as that sounds, for being such an incredible friend to her and always being there for her no matter what hurt it caused me, and then her dropping the friendship like it meant nothing. That would make me an asshole, but the ethical dilemma is should the "baby daddy" be told the truth so he knows? I would think if I was not involved that he should be told for his own happiness, but I have to admit my driving force is revenge. 

So yea, WIBTA for telling the "baby daddy" of my ex-best friend that it's not his kid?