Donna Kauffman 
Her Secret Thrill [EPUB ebook] 

The proposal: Get together whenever their heavy travel schedules overlap Natalie Holcomb’s impulsive — and uncharacteristic — night of steamy sex with a gorgeous stranger was supposed to be a onetime-only affair. But straitlaced Natalie is determined to play by the rules and get more of what her body is craving….The ground rules: Keep the relationship strictly sexual Jake Lannister may live in another town, but after his incredible night with Natalie he just can’t say goodbye. But when Jake’s lust turns into something more, he’s faced with an unfamiliar problem — honor his rules and ignore his building emotions, or give up sex this good and risk losing what he has with Natalie?