The Incorrigible Courtesan by Merry Farmer

Gambling with your reputation has never been so much fun!
The Disaster at Almack’s was the beginning of the end for Miss Honor Barnes, even though her part in it was small. With her reputation in tatters, she must look for ways to secure her comfort and safety…which is where wealthy tradesman, Sebastian Boothe, comes in. And if it means a daring gamble at the card table to win her way into his bed, it’s a chance she’s willing to take.
Sebastian is just enough of a rake to bow to Honor’s wicked wishes, but he has more than fun on his mind. His entire fortune is in danger, thanks to the underhanded machinations of Lord James Grey. With time running out to prove he is the rightful owner of the profits of his recent trade mission to India, he is faced with the impossible unfairness of a commoner challenging the nobility.
But Sebastian has an ace in his corner in the form of Honor and her skills. Together, they can set a trap to take down the most notorious cheat in the ton…if Sebastian can learn to trust Honor first.