Why is my friend doing this to me?

ok so my friend is 15 and im 13 and theres this guy (our friend) who like me and she KNOWS i DONT like him but shes making him flirt with me and saying im being mean and stuff for not flirting back i told him i dont like him i told my friend to stop but she wont and im not trying to be mean ir anything but hes kinda ugly so shes almost making it seem like im desprate and she keeps telling him i made him sad when shes the one who keeps getting his hopes up but if i tell her to stop again and tell her how i really feel shes going to get nad at me again and last time we had a fight itvwas almost the end of our friendship cuz she said she never wanted to be my friend again until sge realized it really wasnt my fault but i really dont want to get in a fight with her cuz shes lives in another state (the state i grew up in) and im going there nxt week and i leave on wedsday so i dont want her being mad at me :( please help what do i do!? and why is she doing this? (oh and she has a bf and they are happy together)