Salt Kiss by Sierra Simone

After being a soldier, working as a bodyguard should have been keep the owner of DC’s ultra-secret club safe, don’t think about his midnight eyes or his devil’s smile, don’t surrender my body to his wicked desires. But I underestimated Mark Trevena and the power of his dark, seductive world. I underestimated the hold he’d have on me, the way I would do anything for him at all. And so when he asks me to escort his soon-to-be bride home, I can only—miserably, broken-heartedly–say yes. Isolde is nothing like I expect, however. Quiet and lonely and sharp, a girl who likes knives and God, a girl whose nightmares echo my own. One night while sailing under the cold stars, we share a reckless, tear-soaked kiss. I’m doomed. Falling in love with Mark was one thing, but his bride too? Being in love with a husband and wife at the same time? Torture. Misery. A tragedy if tragedies came with bruises, sweat, sighs.
But it isn’t enough to merely fall into the forbidden. Because in Mark Trevena’s world, the fall is only the beginning…