Ateuma Chara no Kuse shite, Super Darling Ouji ni Chouai sareteimasu.

Side Character — Unimportant. Constantly getting in the way of the main characters' love story.
After finding himself reincarnated into the world of a novel, Loneal goes to great lengths to steer clear of Prince Alec, the hero, to avoid disrupting the main storyline between Alec and the heroine, Lily. However, to Loneal's great surprise, the prince becomes infatuated with...him?!
"A charming physique, such as yours, more than makes up for your lack of experience."
Before he knows it, he finds himself melting into the prince's arms... Why is everything so different from the novel?!