Intent to Seduce by Cara Summers

Dr. MacKenzie Lloyd is determined that no husband of hers will ever leave, so she's learned everything there is to know about the art of pleasing a man. But now it's time to put her knowledge into practice, and when she finds herself alone with seriously sexy CEO Lucas Wainwright, Mac decides to see if practice can make perfect. Lucas had no idea how incredible sex could be, until Mac becomes his every fantasy in the flesh. But once Mac has proved all her theories, will she start looking for another test subject?

A Glimpse of Fire by Debbi Rawlins

One look at the mannequin in the Manhattan department-store window and ambitious executive Eric Harmon knows no woman could be that perfect. But the leggy blonde is actually ex-model Dallas Shea, and when he spies her at a stuffy corporate dinner, he's got to find out if the mystery woman feels as authentic as she looks. Good thing Dallas is aroused, too. Being Eric's mystery woman has had her hot 24/7! But there's only one way to keep the embers burning. Reveal nothing about herself, play up the fantasy. And pray he never gets more than a glimpse of the truth.