Xbooru - 2010s 2017 2boys 2d 2d (artwork) animated skeleton big dom big dom small sub bigger dom bigger dom smaller sub bigger male blue blush blush bottom sans bottomless brother brother/brother brother and brother brother penetrating brother brothers closed eyes clothed clothed male digital media (artwork) drooling duo facing another fontcest incest larger male larger penetrating larger penetrating smaller male male only male penetrated male penetrating male penetrating male mastery position monster orange blush papyrus papyrus (undertale) papysans penetration sans sans (undertale) seme papyrus sex sinfulsanspar sitting on another sitting position skeleton sketch small shirt small sub big dom smaller male smaller penetrated smaller sub smaller sub bigger dom top papyrus uke sans undead undertale undertale (series) video game character video games white background yaoi