It's not your fault. He came onto you. He's going out with someone, just let him know, that as long as he's going out with someone you can't be together. Even if his gf likes him that much while he doesn't back, would she really want to be going out with him if she knew that he didn't feel the same?.. I know I wouldn't.
Think about it. It's not your fault, it happens all the time.
All my friends are skeletons,
dulcimers and chariots
prayers to God, oh prayers to God
Was I sleeping all this time?
Was my shadow ever mine?Wintersleep-Danse Macabre