

When Izuku brings his beloved boyfriend home for the holidays, he discovers his uncle's depraved obsession: Katsuki Bakugou masturbating with his under garments. From the shadows, Izuku watches, horrified and aroused, as his own hand moves in a traitorous mirror of his uncle's lust. Trigger Warning: Incest, Voyeurism, Grooming, Public Sex, Cheating, Panty Theft, Risky Sex
Izuku and Shoto are in college talking about winter break. Izuku pops the question asking if Shoto wants to come meet his family. He nervously explains they’re a lot and he doesn’t have to. Shoto smiles warmly and agrees.
The traveling is hectic, but quick when flying. Izuku tries to prep Shoto to meet his family while they travel. Trying to tell him everyone who will be there and their relations to each other. Izuku is obviously nervous and the final one he explained is his Unlce Katsuki (Izuku has always called him Unlce Kacchan since he was a kid) who he seems extra nervous about. Shame filling him at remembering masturbating in the shower.
The headboard of the guest room tapped a slow, insistent rhythm against the wall they shared. Izuku lay frozen beside a sleeping Shoto, his own hand trapped under the covers, fingers curled into a guilty fist. Each muffled thud was a pulse between his legs. The world had narrowed to this sound, this shameful enjoyment of hearing Uncle Kacchan fucking his husband.
The next day the rest of the family arrived and everyone was all under same roof enjoying each other’s company. Everyone was happy to meet Shoto and Shoto even bonded with Denki since Denki had to do this last year. That night they have a big family dinner all together.
After Izuku cleans up his room and himself he catches Katsuki in the hallway just before the stairs. They have a moment of awkwardness and not sure how to act with each other. Until Mitsuki walks up the stairs and interrupts their staring contest. She asks where they disappeared to. Katsuki quickly makes up an excuse as Mitsuki passes them to get to the bedroom she’s sleeping in. Once alone again, Izuku quickly pulls his lacy dirty panties he was wearing out of his pocket and shoves them in Katsuki’s jean pocket. Izuku then rushes back downstairs to join the family and Shoto. Katsuki pulls out the lacy panties to see what Izuku just gave him. When he sees what they are and smells Izuku’s squirt on them, heat goes right back to his cock.