She tried to kiss my boyfriend, infront of me ?!!!?

Ok so my friend's parents where on holiday and about 10 people (our closest friends) came round for a quiet night in. There was alcohol and every one bar my on friend Kara* were drinking very light because it was not a party or a wild night just a calm little night in , i must stress this point. It was also the first time i introduced my boyfriend of a month to my friends, which was also why were were just drinking very light (lambrini and the occasional malibu mixer). Any way Kara became drunk and tried get very close to my boyfriend and i jumped in the way because i know her well and know how she tries to make a move on a guy. This was the first time she tried to kiss him but i got her away and decided to by pass it because she was drunk and it could of been anyone. However when the majority of the group went outside for a minute to see our friend who was walking his dog and to see if he wanted to come in but he told us , that he couldn't because he hadn't packed his case for holiday the next day. I went to the house through the side door and on the bins was my bf because he didn't know our friend so stayed there because it was only for a minute and i saw my boyfriend trying to pull himself away and push Kara away because she was trying to pull his head down so she could kiss him. He hadn't seen me so it wasn't an act, which is a very good sign. I screamed her name and ran up to help get her away from him, but i am extremely angry with her but she claims she can't remember either but what should i do about her ?