Ii Ko ni Suru kara Tojikomete

I'm your hostage, so you can have your way with me. A stubborn older king and a devoted noble prince navigate their love in this fantasy BL! Prince Lim has offered himself as a hostage to the palace of the neighboring kingdom of Suyarvilette, all so he can meet his first love, Finn, the man who was once in charge of his education. No matter what Lim does, he can't shake the complicated feelings he has for the man who took such good care of him as a child. Lim tries to close the distance between them using his status as a hostage as an excuse, but Finn refuses to budge and begins making preparations to send Lim home. Lim can't stand to be away from his beloved, and, in an attempt to get Finn's blood pumping and seduce him, invites him by saying, "I'm an adult now"... (Source: Coolmic)