bakudeku

Izuku and Katsuki had been a couple since middle school, but Katsuki's pride had made the relationship difficult. The blonde loved him, but the problem was the lack of communication; Izuku would fight with him, and they argued more and more, reaching a point where he truly didn't want to speak to him. Izuku put everything into the relationship but received nothing in return.

Hatsume asked Izuku for help as a test subject. Izuku helped, but just when he thought it would be an explosion job because of her "baby"—a prototype that was supposed to be a guy with a teleportation quirk—a man similar to Katsuki emerged from the smoke of the explosion, only he was more "wild," more medieval. The savage Katsuki refused to leave modern Izuku's side.

After the incident, the medieval Katsuki was the complete opposite of his boyfriend; he gave him attention, affection, and cuddles. It turned out that medieval Katsuki had a husband, and that was the one from the past, meaning that in his eyes, it felt normal to do those things with modern Izuku.

But the one who was not happy was Katsuki, jealous of seeing him happy with another.