Xbooru - ... 2010s 2015 2boys 2d 2d (artwork) animated skeleton big dom big dom small sub bigger dom bigger dom smaller sub bigger penetrating bigger penetrating smaller blue tongue bottom sans brother and brother brother penetrating brother brothers calciumchan closed eyes clothed clothed sex digital media (artwork) drooling english text fontcest frisk frisk (undertale) from behind from behind position gloves heart-shaped pupils heart eyes heart shaped pupils hoodie hot dog hotdog human humanoid focus incest male papyrus papyrus (undertale) papysans penetration penetration from behind penetration through clothes public sex red gloves sans sans (undertale) seme papyrus sex sex from behind skeleton skeletons small sub small sub big dom smaller penetrated smaller sub smaller sub bigger dom speech bubble spoken ellipsis stealth sex sweat text text bubble tongue tongue out top papyrus uke sans undead undertale undertale (series) v v sign video game character video games