Xbooru - 2010s 2018 2boys 2d 2d (artwork) animated skeleton arm grab big dom big dom small sub bigger dom bigger dom smaller sub bigger male biting biting shoulder black background bleeding blood blue blush blue tongue blush bottom sans brother brother/brother brother and brother brothers clothed clothed/nude clothed male clothing dark background digital media (artwork) dominant dominant male drooling duo ectotongue edit edited fangs fontcest glowing glowing eye incest kneel larger male long image lowest-of-dirt lowest of dirt male male/male male only maledom malesub monster nude orange eye papyrus papyrus (undertale) papysans sans sans (undertale) seme papyrus sequence sequential skeleton small sub small sub big dom smaller male smaller sub smaller sub bigger dom submissive submissive male tall image third-party edit tongue tongue out top papyrus uke sans undead undertale undertale (series) undertale fanfiction video games yaoi