What should i do about a guy i love?

i love this one guy, it started because he used to "play me" we were pretend dating. i fell for his game and now i love him. he aleady knows i love him, but he doesnt believe me. he is straight, but i think he is bi because of what he does to other guys ;] anywhoo, i want to make him understand i am the one he is looking for, i want him to know i am the one he should love. he has asked out numerous amounts of girls yet they all reject him. how do i show him the love i have for him is real and unconditional? btw, were both 15 and im bi and he claims he is striaght but because he does perverted gay things with other guys, i think he is bi