AITA for telling the girl who kissed my boyfriend for a play that she is desperate and pathetic?

I (19f) study drama at uni, and my boyfriend is on the same course. My boyfriend is a really good-looking guy, but he doesn't seem to know it. He gets a lot of attention from girls and for the most part, doesn't seem to get that they're flirting with him. I'm not generally annoyed by this, and never really say anything.

However, there's one girl in our class, let's call her Victoria, who is obsessed with my boyfriend. She goes out of her way to be paired with him in group activities (for example, if the professor picks groups by numbering us 1, 2, 3, she will move herself to be in the same number as him) and she recently stepped down from a main role in a play we're doing so she could be in a more minor one, simply because this character has a romance with my boyfriend. I know this is the case, because I've heard her say to her friends that she thinks he's hot and what not.

I've never said anything to her about it, because she seems pretty insecure (always complaining about how she thinks she's ugly) and I don't see it as a big deal because my boyfriend doesn't care. However, we recently performed the play and had a small afterparty where she got slightly drunk and was bragging about how she 'definitely felt something' when they kissed in the play and she's 'going to ask him if he felt the same'. I rolled my eyes and again ignored it, until she actually went up to my boyfriend. She was a little bit drunk, and when she went up to him I was there too.

Victoria started saying that she knows he must have felt a spark, he's a really good kisser, etc. I snapped, and sort of shouted at her that 'you sound incredibly desperate, going after somebody else's boyfriend. You're pathetic if you think a stage kiss means you should be together.'

She looked super embarrassed and walked away, and I later heard she'd gone home crying. I feel like a dick because she's obviously insecure and whatnot, and her friends haven't stopped calling me a bitch since. AITA?

Edit: She 100% knows that I am his girlfriend, I have heard her talking about me being his girlfriend before.