It is what you have to do is go out with you this matter have told him already let the judge everything, because I think that if he likes you, he probably will continue to be friends with him again.
It's a few things you can do is to tell him you keep it with you and let time be the judge of everything. Because I think that if he really likes you, he'll be dating his girlfriend for another time.
There are things that you can do a few things. Are you going to tell him. You keep it and let the time decide everything. Because I think if he likes you, he would go out with his girlfriend the next time.