Cold Hearted Casanova (Cruel Castaways)

Cold Hearted Casanova (Cruel Castaways #3) by L.J. Shen

Riggs Bates may be a billionaire, but he knows money can’t buy happiness. He keeps his financial status a secret and takes his women the same way he takes his meals—a different one three times a day. That’s until he’s caught sleeping with a married newswoman by none other than her ambitious assistant.
Daphne “Duffy” Markham wants two things in life: marry well and stay in the States. So when her almost-fiancé takes off to “find himself” and her work visa approaches expiration, Duffy resorts to the only thing she has left—blackmail. Luckily, Riggs needs an excuse to stay in New York as badly as she does, so their first meeting quickly leads to a begrudging engagement.
Armed with strict house rules and their mutual distaste for one another, Riggs and Duffy soon find there’s no denying the spark between them…or the fact that this fake marriage is starting to feel a little too real.