AITA for Kicking My Sister Out After She Brought My Ex to My Birthday Dinner?

I’ll start by saying I’m not a dramatic person. I really try not to be. I’m the peacemaker in the family, the “just let it go” one. But this pushed me way past my limit, and now I’m the one getting texts about being “immature” and “making things awkward for everyone.”

It was my 29th birthday last Saturday. Nothing huge—just a dinner at my place with some friends and family, homemade pasta, wine, vibes. My roommate helped string up lights on the balcony, my boyfriend (well… ex-boyfriend now, we’ll get there) brought a cheesecake from this bougie bakery I love. I was actually excited, which is rare for me on birthdays.

My sister Anna (24) asked if she could bring someone. I said sure, thinking it was her on-again off-again girlfriend or maybe a work friend. She said “you’ll recognize him,” and laughed, but I thought she was just being annoying. Turns out, she brought Jake.

My ex. The guy I dated for three years.

The guy who cheated on me with a coworker and then cried when I broke up with him “because it wasn’t emotional cheating.” That guy.

Things Got Weird Fast

I opened the door and there he was, standing behind Anna with that dumb apologetic half-smile. Like this was a sitcom and I was supposed to go, “Jake?! What are you doing here?!” and then laugh and hug him. Instead, I just stared. My stomach dropped so hard I actually thought I was gonna puke.

I said, “What the fuck is he doing here?” And Anna goes, “Don’t be dramatic. We’ve been hanging out again, and I thought enough time had passed.”

That. Exact. Sentence.

Like I was being ridiculous for still having boundaries. Like the pain this guy caused me could be neatly filed away because she decided it was convenient.

She kept trying to brush past me into the apartment like this was no big deal, but I blocked the door. Jake had the nerve to say, “Hey, I just wanted to wish you a happy birthday, maybe talk.”

I snapped. I said, “Get the hell out. Both of you.”

My voice cracked, which made me feel even worse. Anna started yelling that I was being a bitch, that I was ruining my own party, that Jake was just trying to make amends. I told her she could make amends with him all she wanted—at her place. Not mine. Not tonight.

She finally stormed off with him, slamming the door so hard the string lights flickered.

The whole apartment went quiet. My boyfriend (well, my boyfriend at the time) just kind of stood there awkwardly with his hands in his pockets. One of my friends whispered, “Holy shit,” like it was a movie.

I went to the bathroom and just sat on the edge of the tub for ten minutes. Couldn’t cry, couldn’t scream. Just… numb. I came back out, said “Let’s eat,” and tried to act normal.

But the rest of the night felt off. The vibe was weird. Everyone was polite, but it was like we were pretending we weren’t all thinking about what had just happened.

After the last guest left, my boyfriend said, “You know, I get why you were upset, but you kinda blew up.”

I asked him if he would’ve been cool with his sister inviting his cheating ex to his birthday dinner without telling him. He said no, but “it’s not black and white.”

Two days later, he broke up with me. Said I “hold onto things too long” and that he felt “emotionally exhausted” by my reactions.

Cool. So now I’m 29, single, and barely speaking to my sister. My mom says I “overreacted but from a place of pain.” My aunt texted me, “Maybe talk to Anna? She probably didn’t realize how much it still hurt.”

But like—how could she not?

Jake humiliated me. My sister was there when I sobbed on her couch for weeks. She let me crash at her place when I couldn’t stand being in the apartment Jake and I shared. And now she’s dating him? Bringing him to my birthday?

There’s a part of me that wonders if I was too harsh. If I’d just pulled her aside quietly and said, “This hurts me,” maybe we wouldn’t be here. Maybe she would’ve understood.

But there’s another part of me that keeps flashing back to the smug little smirk Jake had when I opened the door. Like he knew what this would do to me. And Anna let it happen.

So… AITA?