The Dark Master - Romanian Chronicles, #1

Grayson Edwards was excited to enter The Service but found that he was not satisfied with his new Master. After completing his assignment, he contracts with the State Department, specializing in negotiations. His party is beset with accidents and bad luck, including a car crash. Grayson wakes up in jail but is rescued by Alexander Radu, a member of Romania's royal family. Alexander Radu can do things that Grayson can't wrap his mind around.
Grayson thinks his biggest decision is whether to become Alexander's sub or not, but there is an even bigger choice for him to make when he discovers his dark secret.