The duke in my bed

"As a notorious member of the Heirs' Club, Bray Drakestone can't resist a challenge from one of his well-heeled colleagues--especially when it involves money and horses. But the friendly wager takes an unexpected and deadly turn. Bray is forced to agree to marry one of his challenger's five sisters--sight unseen. Now gamblers all over London are placing bets on whether Bray will actually go through with it"--Amazon.com.