'AITA for telling off my sister at her birthday dinner?' 'The mood turned SOUR.'

"AITA for telling off my sister at her birthday dinner..."

Here's some important context: My sister (28f) recently got engaged to her now fiance (28m). We only recently found out about the engagement even though they've been engaged for 2 months. Before their engagement they were only dating for a month or so.

When my sister announced her engagement we were all shocked to say the least but we congratulated her and we celebrated. However, she has now made it a point to stay making fun of the fact that she got engaged before me (25f) even though I've been in a long distance relationship with my bf (28m) for 4 years.

In fact everyone was surprised that she got engaged before me. I've told her multiple times that I'm not bothered that she got engaged before me since she is the older sister so it only makes sense.

Now here us where I might be TA. We were at her birthday dinner a few days ago. Once again at this birthday dinner she started the whole thing of how she got engaged before me. I was just going to let it slide since it was her birthday dinner and her fiance was there and I don't really know him that well.

However she then said that they were planning that if they found out that my bf was going to propose to me they were going up get engaged the day before just to beat me to it. As soon as I heard that I lost it and told her that she's making it seem as though she only got engaged just to spite me.

The mood turned sour and eventually we all went home. My parents think I overreacted since according to my sister that comment was only a joke. So AITA for telling off my sister at her birthday dinner?

Here's what people had to say to OP:

twothirtysevenam said:

ESH. Your sister is in some weird competition to be first. Being the oldest does not matter. Your reaction sounds less than mature. Your parents getting upset that you were upset certainly isn't productive.

MrBreffas said:

Your sister is behaving like a toddler. Do not rise to the bait -- it only makes you look foolish. Sure, you overreacted; only because she didn't deserve any response at all -- but she was indeed acting like a spoiled child.

__The_Kraken__ said:

NTA, but this is where you need to bust out your pitying look. She’s pathetic and everyone can see that, so don’t let her get under your skin.

brent_bent said:

Your comment was only a joke too, that's what you tell everybody.

YogurtclosetVast3118 said:

Just point out that she will get divorced before you... because you don't marry the first loser that asks you and you'll stay married. NTA.

Akasgotu said:

NTA. You didn't "tell her off," you brought her motivation into the light and she didn't like how it looked.

MixOk5450 said:

NTA: That's a really specific joke, and jokes are supposed to be funny, not mean-spirited