Is he in the wrong or am i?

To be perfectly honest with you darling, you were both wrong. You both are in a relationship andhave been disloyal i guess. Though i understand what you mean. Talk to this guy and ask him what he really wants, he may only want to use you and just sleep with you whenever he wants but nothing serious. If thats the case you don't need him and you should forget all about it. If he is serious and wants to be with you, then you need to talk to your current boyfriend. You still like this other guy and the longer you leave your boyfriend, the more upset he'll be when you break off with him. Good luck honey! :)