'AITA for saying yes when my BF proposed at my sister's (his ex's) bday party?' UPDATED

"AITA for saying yes to my boyfriend's proposal?"

So, basically, I'm 24NB. My boyfriend (Fiance?) is 25M. My sister is 26F, and I don't know the ages of most of her friends, but roughly the same age. Now, my sister and my boyfriend/fiance do not get along well.

I don't really know what happened. I think my sister is just upset because she has issues with commitment, and she dated him at their high school (I went to a different high school), and then cheated on him, and is upset he broke up with her. I met him in college, and didn't know it was him.

Now, what happened is, last week it was my sister's birthday. She was always into stupidly lavish things, we both are, so she threw a big birthday party at a venue in the forest. Me and my boyfriend/fiance were both invited. We've been dating for a few years and he's never been invited to one of my sister's birthday parties before, so we were both thrilled at this development.

At the party, my sister was busy opening all her presents, then eating cake, both of which we were there for. Afterward, my sister started talking to her friends, and the guests started to explore the area. It was stunning. Me and my boyfriend were a little bit away when we found a little clearing. We were still pretty close to the venue, but I think it was pretty private. My boyfriend thought so too.

He got down on one knee, and proposed. He didn't have a ring, he had one at home though, but he had woven a ring out of grass while we were walking (we are both very fidgety), so he put that on my finger after I said yes.

Apparently it wasn't as private as I thought, because when we got back to the venue after taking a selfie and scheduling a post for a few hours after the party was scheduled to end, I was bombarded by a shower of congratulations. Turns out my sister's friend, "Lisa", saw my boyfriend propose, and then came back to the venue and told everyone.

I figured that I could show them the ring, and tell the story, and then move on from that and back to my sister. While I was being congratulated, another girl, one of my sister's best friends, came up to me, asked to see the ring, and told me that "Wow, he even skimped out on a ring. He couldn't plan his own proposal, or get you a nice ring."

I was upset, because I wasn't even planning to tell anyone. If someone noticed the ring, I would tell them, but I wasn't going to announce it to the world, or do it in public where everyone can see us. We left immediately afterwards, and my entire family has been blowing up my phone calling me an attention seeking b-word, and that I shouldn't have done that to my sister.

I'm worried I might be an @$$hole because it was my sister's birthday. and if I said no maybe she wouldn't have been upset about my boyfriend proposing.

What do you think? AITA? This is what top commenters had to say:

Ok_Possibility5715 said:

YTA but mostly your fiance is. Especially since he dated you sister in high school. Even though we don't know how serious? Maybe her first? It was her birthday party. And also sorry but you say you don't know why they don't get along? Because they have a past together of them dating and how i understood it her cheating on him? YTA

Juststrathmore said:

YTA. But mostly, your boyfriend is 100% TA. I can’t believe he thought it appropriate to propose at your sisters event. I can’t believe you didn’t shut it down, due to the clear disrespect he’s showing to your sister.

Also to you. He’s disrespecting you here too. Does it not bother you that his proposal, which should have been your moment, something just between the two of you, is now intertwined with his ex girlfriend?

It seems like he did that on purpose to me. You don’t spontaneously propose at your ex girlfriends birthday party. That takes a great deal of spite. It’s beyond the realm of being accidentally clueless. It looks like he used your moment - your proposal - as a way to say eff you to his ex girlfriend. There’s a lot of things you could have done here.

Tangerine_Bouquet said:

This is a hot mess and ESH. Lisa probably sucks most of all for spreading the news after watching a private moment. Your fiance definitely sucks for proposing at your sister/his ex's birthday party.

You suck for not understanding that this proposal was inappropriate, and apparently not understanding why your sister wouldn't be very comfortable with your fiance around or discussing/working out issues.

Yes, she would be upset you're marrying an ex of hers no matter the circumstances. Your sister probably sucks for cheating, although seems blameless in this particular situation (even invited you and your fiance, mending relationships).

Destroying family relationships in this way is immature. Both you and this guy are apparently socially clueless and lack empathy (although I can understand his side of not liking your sister as an ex of his who cheated on him). You are participating in his payback, though, and that's Grade-A AH behavior.

bubblez4eva said:

I don't think there's anything to think over, please just end it with this man. He used you just to hurt your sister, and that's all you need to know.

OP responded:

I'm going to try and talk to my sister first. I want to hear everything from her side, not through word of mouth.

Update:

Hey guys, I'll probably do a more complete update later, but scrolling through your posts kind of awoken something in me. I've never been good with people (Undiagnosed Autism), so it didn't occur to me that my BF might have been lying about my sister.

I told him that I was going to be thinking about some things, gave him back the ring, and called a friend we both knew in high school. He said that apparently my BF was lying.

See, I was in a student exchange program when they were dating. So I never knew what happened, since the drama died down before I got back, but apparently my BF not only lied about my sister cheating, but also lied about why they stopped getting along.

Yeah. Apparently, not only did my sister not cheat, the reason they broke up is because my BF did. Cheat that is. At least that's what the rumors that went around said. Neither of them shared. And then he tried to sleep with my sister, which is why she got cold around him again. She didn't tell me because she didn't want to ruin my happiness.

So as far as I can tell, he might have proposed to me as a twisted revenge scheme of some kind. I'm thinking about it all over.

I will make another update post later when I've figured all the pieces out.