A Gamble on the Duke by Emily E K Murdoch

Alfred, Duke of Kineallen, never accepts defeat.

And that’s exactly why I need to find a woman to pretend to be courting—because the potential saviour of the Gambling Dukes requires a business partner who’s ready to settle down.
So what do I do? Find a placid debutante, perhaps speak to another duke and choose his daughter?
No. I literally run headfirst into a lady with no manners or sense, make her a proposition she can’t refuse, and move Miss Catherine Shenton into my house.
Precisely why I’m also finding her in my mind, my dreams—my longings—I couldn’t say…
Only one person can win a gamble on the duke: and it’s got to be me. If I lose this gamble, I’ll lose myself to Catherine Shenton…