I have a girlfriend of 3 years which I do love and she's a nice person. She's attractive, caring, has a lot of qualities a woman should have (knows how to cook, isn't messy, cleans the house, knows I'm her man and most importantly, isn't a leftard). The problem started with one girl who has fallen in love with me. She never explicitly said that but everyone is talking about it and her actions prove it. You be the judge after this post. First some things about her: she's really rich (both parents MDs, owns a BMW X1 while being a student and not working), she want's to be in the center of attention, loud, 7/10, thinks she's 11/10. I'm not that rich (average) and I heard her say she wants her future BF to be as rich as her and spend a lot of money on vacation with her, restaurants etc. We're in the same group on lectures and she's always wanting my attention. For example she makes fun of me in front of me just so I would talk to her. She filmed me dancing with another girl on a party just so she can threaten me she'll send it to my GF. I'm literally only dancing. Yesterday things were brought on another level. I have a fat friend in the group who makes fun of his weight, we roast him, he roasts us and no one gets offended. But for a bystander it sounds cruel. She overhead me making a joke about him (saying it to him) and attacked me that I'm cruel, a bad friend etc. She's making a big thing out of it and spreading it to every single girl in class. Now they all think I'm a bad person and that I shouldn't be doing it. My friend is just laughing because it's funny to him. I told this girl to leave me alone, to stop messing with my life and I tried ignoring her. It worked for a day. Today, when she was sure I was ignoring her, she started "accidentally" bending her butt towards me so I could see her tongs. She never does that and it wasn't a coincidence for sure. I started thinking about her and is it any good to give her a chance. Is it worth destroying a relationship just to see if it will work out. I'm just doing a pros/cons in my head and I'm biased towards cons. Also, what should I do to make her leave me alone? The best scenario would be if she found a boyfriend, but that's pretty unlikely because she didn't have any I think (she's 21). What would be the alpha way of solving this?

TLDR: A girl in my class wants me and is doing everything to get my attention. I have a GF and I don't know how to manage this situation.