Xbooru - 2010s 2018 2boys 2d 2d (artwork) anal animated skeleton artist name big dom big dom small sub bigger dom bigger dom smaller sub bigger male blue blush blue eyes blue tongue blush bottom sans brother brother/brother brother and brother brother penetrating brother brothers clothed clothing crying crying with eyes open dominant dominant male duo ectotongue fontcest from behind position glowing grabbing grabbing clothing grabbing from behind heart-shaped pupils heart eyes incest larger male male male/male male focus male only maledom malesub monster open mouth papyrus papyrus (undertale) papysans penetration penetration from behind pleasure face realdemdemdmensfw sans sans (undertale) seme papyrus sex sex from behind simple background skeleton small sub small sub big dom smaller male smaller sub smaller sub bigger dom solo focus submissive submissive male tears tears of pleasure tongue tongue out top papyrus uke sans undead undertale undertale (series) unseen male face video games white background yaoi