I really need someone's help. desperateelyy.. relationship problem?

wel basically ive got a boyfriend, in april he wanted to play a game on me, by making some new account, wid hez name and so many girls, i got angry and was about to end it but then he told me it was an april fools day joke and it was an account he got from his friend. i said owk and told him to change hez name and info. he did it but because hez msn was the same i could see de account. i fink hez still using it so i got my friends fake accout and added him, the way he talks is like my boyfriend and the songs he uploads are like his, i didnt make it obvious who i was. my stupid friend told my boyfriend the whole thing, im talking to her, she said it was me talking to the fake account, he kept denying it that it was him and that i was stupid enough to not trust him, i got angry with me badly... how can i prove it if itz him or nott,,, someone tell me, its so obvious that it is him but i want to prove that it is him.......offf :((((( somoneeeee heeeeeeelppp meeeee!!!!