Black is My Heart by Elise Noble

Finding dirt on politicians is usually easy, but Congressman Clements is more careful than most. Never one to back away from a challenge, devious Diamond enlists her old friend Snow in a scheme to catch their target in a compromising position.
But the world of espionage rarely runs smoothly, and Diamond soon finds herself stuck in a tight spot. Can she save the job as well as fight her feelings for the man she loves?