Prince and Assassin (Perilous Courts, Book 1) By Tavia Lark

In "Prince and Assassin," Whisper, an elite assassin controlled by a guild with blood magic, is assigned to infiltrate Prince Julien's court and kill him. Julien, who hides his own schemes behind a sordid reputation, doesn't trust Whisper but is drawn to him when Whisper saves his life.

As Whisper and Julien grow closer, Whisper finds solace in Julien's touch. However, Whisper's mission remains unchanged, and the price for failure is worse than death.

"Prince and Assassin" is a high fantasy gay romance with secret identities, hurt/comfort, and magic tigers with attitude. It is part of the Perilous Courts series, which is best read in order. Each book in the series follows a different prince and his Happily Ever After.