Woman bans sister from borrowing expensive dress for ex-fiancé's wedding. AITA? 'I was FLOORED.'

"AITA for refusing to let my sister borrow my expensive dress to wear to my ex-fiancé's wedding?"

So I (30F) have a younger sister, Mia (27F), and we’ve always had a complicated relationship. She’s often been jealous of me and my achievements. Last year, my fiancé, Ben, dumped me super suddenly and very publicly. He’s now engaged to my former "friend," Zoe. Their wedding is next month, and honestly, this whole thing has been rough on me.

Recently, I bought a stunning, expensive designer dress for a fancy charity event I’m going to next month. It’s a special dress, and I felt like I deserved to treat myself after everything.

Yesterday, Mia saw the dress and immediately asked to borrow it to wear to Ben and Zoe’s wedding. She said, “It’s perfect! I need to look amazing, and you’re not even using it right now.” I was floored.

I told her no, that it’s for my event, and it would feel so wrong for her to wear it to that wedding. She got super mad and called me ridiculous and selfish, telling our parents I’m a terrible sister for saying no. AITA for not letting her borrow my dress, especially for that wedding?

Here's what people had to say to OP:

LdiJ46 said:

NTA Your sister is the AH for even asking to borrow and expensive designer dress that you haven't even worn yet.

Anxious_Reporter_601 said:

NTA why the F would she even go to that wedding?

Kami_Sang said:

NTA - hold to your no. Your sister is going to a wedding of your ex and former friend when just last year you were engaged to that man and he humiliated you. In addition, she wants to wear an outfit you splurged in to make yourself feel better to that wedding. I think there is only one terrible sister here and it's not you.

celtic_glitter said:

NTA and word of advice…never let anyone borrow your clothes or anything else. I’ve found folks either don’t respect your clothes and if they return them, they’re damaged or they don’t return them at all.

kalequinoa said:

NTA. Your sister is a gaping a-hole for even going to that wedding, never mind throwing a hissy fit about your dress. Wtaf.

forgetregret1day said:

You’re 27 and 30 years old, why is your sister still crying to mommy and daddy that she’s not getting her way? That irritates me for one, but what kind of sister would go to that wedding, knowing how much those people hurt you? And in your expensive dress no less? Time to step away from your sister for a while. She clearly doesn’t care about your feelings, just herself. NTA.

PrestigiousFace6756 said:

NTA, why would your sister go to a wedding of a man who hurt you. Don’t let her borrow your dress or anything else.