A Deceptive Wager by Ruth Ann Nordin
Miss Kitty Farrow is under no illusion that her guardian cares anything about her, but when she finds out he wagered her in a gentleman's bet, she's in a state of complete shock. Not only has her choice in picking her own husband been taken away from her, but the earl her guardian is going to have her marry hates the very idea of having a wife at all.
Aaron Henry, Earl of Northton, doesn't trust ladies. Any of them. From a young age, his mother taught him that all a lady is good for is an heir. If they're sweet, it's only to trick the gentleman into doing what they want, and once they get it, they're on to the next gentleman. So when he discovers the money he expected to win in a wager turns out to be the dowry of his future bride, he wants nothing to do with her.
But whether Kitty or Aaron want the marriage or not, it's going to happen. And heaven help anyone who tries to make the marriage a love match.