Not sure what to do ? help :(?

hes putting you second. basically is just putting you there so if him and his girlfriend brake up he has you to run to. he doesn't have feelings for you like he does with his girlfriend, your just his little side girl. he's cheating on his girlfriend with you and the thing is that you know he is doing it. thats not the right thing to do you should just keep distance form him to show him that you are serious about this and you just want to be friends with him. someone better will come along for you anyway.