A man who regularly promises things to a woman that he is involved with, (i.e. commitment, a future together, etc.), when he has absolutely no intention of making good on these promises. Very cold, calculating, and manipulative character, but with a very soft, kind, likeable exterior.
If you have dated/broken up with a man a dozen or more times, chances are you are involved with a mindfucker and should get out while you still have some of your dignity. And self-respect. And sanity.