If he can't keep a woman around while being a billionaire I'd say that mental illness is called "ego".
I knew someone who was a "mere millionaire" who had the same problem.
It's not ego. Women don't come labeled with tags that say "sincere" and "gold digger" so you can tell who loves you because you're a wonderful person and who merely loves your wallet.
That's the real ego problem. Most of us would like not to have the "love" leave when the money does. Or, for that matter, when a higher "bidder" comes along.