Xbooru - 2d 2d (artwork) ahegao animal animated skeleton annoying dog (undertale) beastiality bigger penetrating bigger penetrating smaller blue tongue bonetrouble bottom sans bottomless brother brother/brother brother and brother brother penetrating brother brothers canid canine carrying carrying partner digital media (artwork) dog english text feral feral on male feral penetrating feral penetrating humanoid fontcest heart heart-shaped pupils heart eyes hooded jacket hoodie implied double penetration implied penetration implied sex incest larger male larger penetrating larger penetrating smaller legs apart legs spread male male/male male/male/male male ahegao male only male penetrating mammal monochrome monster papyrus papyrus (undertale) papysans reverse suspended congress sans sans (undertale) seme papyrus skeleton smaller feral smaller male smaller penetrating solo focus spread legs text threesome toby fox tongue tongue out top papyrus uke sans undead undertale undertale (series) unseen male face video games white background yaoi zoophilia