Xbooru - 2010s 2017 2boys 2males anal animated skeleton bed sheet bigger dom bigger dom smaller sub bigger male bigger penetrating bigger penetrating smaller blue blush blue hoodie blue jacket blue penis blush bottom sans bottomless brother brother/brother brother and brother brother penetrating brother brothers clothed duo ectopenis fingers interlocked fontcest from front position gay gay sex gloves grabbing sheets gripping sheets hooded jacket hoodie incest indoors interlocked fingers intertwined fingers larger male larger penetrating larger penetrating smaller male male/male male only male penetrated male penetrating male penetrating male missionary position mmmemmo monster orange blush papyrus papyrus (undertale) papysans penetration penis red gloves sans sans (undertale) seme papyrus sequence sequential sequential art sequential set sex skeleton small sub small sub big dom smaller male smaller penetrated smaller sub smaller sub bigger dom sweat top papyrus uke sans undead undertale undertale (series) visible breath yaoi