Xbooru - 2020s 2021 2boys animated skeleton bigger male black and white bottom sans brother brother/brother brother and brother brothers carrying carrying another carrying partner clothed cussing duo fontcest from behind hand in pants incest larger male male male/male male only monster papyrus papyrus (undertale) papysans pixiv id 3871107 profanity sans sans (undertale) seme papyrus shorter male size difference skeleton sketch smaller male swearing taller male text top papyrus touching crotch uke sans undead undertale undertale (series) white background yaoi