My Dilemma

I've got a buddy who is a truck driver, and he's gone for two weeks at a time. His wife, who is 4 years older than me is mostly attractive, but not really my type. She has a problem with spending money they don't have, and they struggle financially anyway. While he's been on the road, I've had to bail her out for bad checks, buy her a tire, and pay their electric bill twice.

I try to look after her when he's gone.

She begs me not to tell him, and he's a proud guy that would be humiliated to find out that they are now $1800 in debt to me because of her bad choices, and his thin income.

Telling him would cause all sorts of trouble between them, and she's terrified to tell him even though she's doing nothing to pay me back. She can't pay me back.

Do I tell him and put a stop to it; forget the money; or make his wife pay me back in sex?

I like him, but I have no respect for her anymore, and its not like she's going to tell him. Hell, maybe she'll straighten up and quit begging.