I DO have a suggestion, but I'm not sure you'll like it - LET HIM GO.
Look - you're young, unmarried, no kids yet. Do you really believe this guy is the best you can do for a future spouse, partner, father of your children? He has ALREADY shown you he is capable of betrayal and dishonesty.
YOU need to behave like a woman who thinks she is worth much more than that. He's much more likely to come back if he's seeing YOU around town with handsome young men. But I caution you, he has already shown you something very disturbing about his character.
