Xbooru - 2020s 2023 2boys 2d 2d (artwork) all fours animated skeleton big dom big dom small sub bigger dom bigger dom smaller sub bigger male black background blanket blue blush blush blush lines bottom sans boxers (clothing) boxers around one leg brother brother/brother brother and brother brother penetrating brother brothers clothed clothing dark background digital media (artwork) duo fontcest from behind position hat headwear hooded jacket hoodie implied bottomless implied penetration implied sex incest interlocked fingers intertwined fingers jacket larger male larger penetrating larger penetrating smaller male male/male male only male penetrating male penetrating male monster nightcap on bed one eye closed orange blush pajamas papyrus papyrus (undertale) papysans polka dot clothing polka dot hat polka dot pajamas sans sans (undertale) seme papyrus simple background skeleton small sub small sub big dom smaller male smaller penetrated smaller sub smaller sub bigger dom striped bottomwear striped boxers text top papyrus topwear toubigaizi uke sans undead undertale undertale (series) video games yaoi