bestfriends / sex

so my best friend knows I slept with this guy I like and then she went and got with him at a house party we were all at (I didn't know and was also with him again at that house party). also one of my other bestfriends has recently started seeing this guy (also at the house party) which she was also all over I walked in in her just sitting on him in a closed room and she shouted it's not what it looks like straight away. what do I say to her. why dose she go after any guys any of the girls like. I've been bestfriends with her since we were 5 now 19 I love her but fuck me she talks a serious amount of shite😂