I'm not in the same boat, so I can only try to imagine being in your situation. It sounds painful. If your husband has no history of this kind of behavior, then this sounds like mid-life crisis . . . a bit late. He may be trying to recapture lost youth.

I think it's harder for men, compared to women, to accept that, with increasing age, sex becomes less central to a marriage. Other things become more important forms of bonding. Do the two of you have other things you do that bring you together?

It may be small comfort right now, but this may be a passing phase. If you want to stay in this marriage, you might want to not make too big a deal out of this. Though I think you may need to talk with him. Does he know that you know?

The money aspect is also disturbing. It doesn't sound like your husband has oodles of dough to splurge on women with. So you definitely need to protect yourself from financial loss. If this is a marriage that he wants to stay in, then I would see about getting him to agree to a rearrangement of your financial accounts that limits his access to them. Maybe the household checking account should be in your name only. Betrayal of the heart is a tough, but look to your economic security. Sequester from him what you can, of your financial assets.