Xbooru - 2020s 2021 2boys 2d 2d (artwork) against the wall against wall alley anal animated skeleton big dom big dom small sub bigger dom bigger dom smaller sub bigger penetrating bigger penetrating smaller biting clothes blue blush blue tongue blush bottom sans bottomless bottomless male brother brother/brother brother and brother brother penetrating brother brothers clothed clothing digital media (artwork) duo ectopenis fontcest from front position goma dango 555 hooded jacket hoodie incest jacket kabedon larger penetrating larger penetrating smaller male male only male penetrating monster orange blush pants around one leg pants down papyrus papyrus (undertale) papysans partially clothed penetration penetration from front penis pinned pinned to wall pixiv id 49095896 sans sans (undertale) seme papyrus sex sex from front shoes skeleton small sub small sub big dom smaller penetrated smaller sub smaller sub bigger dom stealth sex tongue tongue out toony top papyrus uke sans undead undertale undertale (series) video games wall wall (structure) yaoi