I can't remember the title or author of a book.

[gordhead]

I am looking for a book that was part of a series. I don’t know the name of the book or the author. The lead female character works for or owns an adult toy mfg. The lead male character is a housing contractor. The female character and the male character may be old flames/friends. She hires the lead male character to restore her grandmother’s home. While he is working on the house he overhears her on the phone plotting that she is going to use him as a guniepig to test out a toy. He confronts her and of course refuses. I think the series also has a book in which a lead male character is a race car driver. Thanks to anyone who can help me.