He was a young prince newly crowned king (18-22ish) and you are the only one he trusts to keep him safe as one of the former king's most trusted knights/advisers, especially after it comes to light that his father was murdered. He didn't expect him to come running into his bed chamber sword drawn, he hadn't realized how loud he had screamed as he pleasured himself. (Would want to play the king)
Would also be up for playing this as a slash line against the late teens prince who is now king and the knight/adviser.