Honey, this is the oldest line in the book "I'll leave her..."
At the moment he's got it good - two women on the go, one with probably no idea what's going on, the other patiently waiting.
Whatever else he's got going for him, you know two things for sure: he is a liar, and he is a cheat.
You deserve better. Walk away with your head high and don't waste your life waiting for this man, very few do leave their wives in the end.