Rush by Maya Banks

Gabe, Jace, and Ash: three of the wealthiest, most powerful men in the country. They're accustomed to getting anything they want. Anything at all. For Gabe, it's making one particular fantasy come true with a woman who was forbidden fruit. Now she's ripe for the picking... When Gabe Hamilton saw Mia Crestwell walk into the ballroom for his hotel's grand opening, he knew he was going to hell for what he had planned. After all, Mia is his best friend's little sister. Except she's not so little anymore. And Gabe has waited a long time to act on his desires. Gabe has starred in Mia's fantasies more than once, ever since she was a teenager with a huge crush on her brother's best friend. So what if Gabe's fourteen years older? Mia knows he's way out of her league, but her attraction has only grown stronger with time. She's an adult now, and there's no reason not to act on her most secret desires. As Gabe pulls her into his provocative world, she realizes there's a lot she doesn't know about him or how exacting his demands can be. Their relationship is intense and obsessive, but as they cross the line from secret sexual odyssey to something deeper, their affair runs the risk of being exposed-and vulnerable to a betrayal far more intimate than either expected.

*Book One of the Breathless Trilogy