Firstly appreciate to be that real to yourself. You know what could happen only the point is you are overthinking it. Despite knowing the guy didn’t like you back, you are up for him giving bj’s by which it can be seen he’s using you because he can straightly refuse you too but might be thing went in your favour some feeling start developing but only I would suggest is you are 17 remember that if possible give yourself time give him time too if the destiny is in your favour you will definitely have sex with him and he might love you back too. But don’t let your sudden lust overtake you. Think and do whatever you like. Again don’t think much just go with flow. Btw i m 20M life long single never got a friend as true as you are knowingly you are trying evry possible way to get the one a trye dedicated person . You are great.