Xbooru - 2020s 2023 2boys anal animated skeleton arm grab big dom big dom small sub big penis bigger dom bigger dom smaller sub bigger male bigger penetrating bigger penetrating smaller blush blush lines bottom sans bottomless bottomless male brother/brother brother and brother brother penetrating brother brothers cussing dirty talk drooling duo ectopenis english text fontcest from behind position grabbing arms grabbing from behind hi res high res highres incest larger male larger penetrating larger penetrating smaller male male/male male only male penetrating male penetrating male monster naked naked male nude nude male onomatopoeia pants around one leg papyrus papyrus (undertale) papysans penetration penetration from behind penis penis size difference prison guard position profanity sans sans (undertale) seme papyrus sex sex from behind size difference skeleton sketch small penis small sub small sub big dom smaller male smaller penetrated smaller sub smaller sub bigger dom swearing talking to another talking to partner text thrusting tired but horny (artist) top papyrus uke sans undead undertale undertale (series) veiny penis white background yaoi