I think im in love with my best friend.help!?

I really like this guy, I always think about him and I want to talk to him all the time, but hes a bit of a flirt. When he has a girlfriend hes totally loyal so I don't mind that hes a flirt but he flirts with me all the time and I don't know if thats because he likes me or not. I dont know what to so because if I tell him it could ruin the friendship and I would rather have him as a friend than not at all. ..do I tell him or just wait and see if anything happens? X

how about telling him in a tricky way.. like play a truth or dare game ask him who he likes or what he thinks about u and what would his reaction be "if" u liked him more.. as if u are fooling around.. and with his answers u can tell if he likes u or not.. and tell him that u like him too :))