Xbooru - ! ... 2010s 2017 2boys 3koma :v animated skeleton big dom big dom small sub bigger dom bigger dom smaller sub bigger penetrating bigger penetrating smaller blue blush blush bottom sans bottomless bottomless male brother/brother brother penetrating brother brothers comic comic panel dialog dialogue dialogue box duo english text fontcest frisk frisk (undertale) gasp gay grabbing arms grabbing wrist human incest indoors larger penetrating larger penetrating smaller lowest-of-dirt lowest of dirt male male/male nude on floor open door orange blush papyrus papyrus (undertale) papysans partially colored penetration sans sans (undertale) seme papyrus sex sex on floor skeleton small sub small sub big dom smaller penetrated smaller sub smaller sub bigger dom surprised surprised expression text text box top papyrus uke sans undead undertale undertale (series) walk-in yaoi