It just released in November 2006, and is getting mentioned in the December 2006 Essence Magazine, so I imagine a lot of us will be reading this over the holidays.
The gist of My Husband's Girlfriend: a temporarily sexually mismatched couple -- he needs it, she's not feeling it at the moment. They make an arrangement. He can get it twice a month, blow the whistle style only, but he can't get emotionally attached or fall in like/love. From the book title, you can imagine he does.
I did read Cydney's first novel, My Daughter's Boyfriend, which came out a couple years back. Muy hot. Sometimes you can't help who you fall for... or can you?