Prince and Pawn (Perilous Courts, Book 3) By Tavia Lark

In "Prince and Pawn," Corin, the neglected illegitimate son of a powerful family, is expected to follow his magic-gifted brother to the palace as a servant. He allows himself one night of distraction in a stranger's arms, only to discover the next morning that the stranger is Prince Audric's new arranged fiancé.

Prince Audric doesn't want a loveless political betrothal, but he'll do anything for his kingdom. His last night of freedom is a rare indulgence and a terrible mistake. Corin is sweet, beautiful, and sees Audric like nobody else does. He's also Audric's fiancé's younger brother.

Constant proximity hurts when they can't be together. But avoidance is impossible when Corin might be the key to unraveling the conspiracy behind Audric's betrothal—and when Corin keeps fainting into Audric's arms.

"Prince and Pawn" is a high fantasy gay romance with hurt/comfort, forbidden pining, inappropriate use of vines, and more magic tigers. The Perilous Courts series is best read in order, but each book follows a different prince and his Happily Ever After.