Should my friend hate me?

Okey so my friends boyfriend likes me.... Hes 15 and im 13.... i don't like him in fact i dislike him alot!!! So my friend calls me and said "Well obiously your seeing my boyfriend behind my back"!!! I tried to tell her he was spreading rumors about us. but she did't believe me so i left her a message saying " I don't like your boyfriend like that... actually i don't like him at all i think he's a pig, who are you going to believe me your best friend of 5 years or your boyfriend of 1 month?" so I just don't know what to do any more and its so confusing!!! help???