Xbooru - 1boy 2d 2d (artwork) alternate version available animated skeleton arms behind back artist request black background blue blush blue eye blue jacket blue penis blush bondage bottom sans bound bound arms clothed digital media (artwork) ectopenis jacket looking at viewer low res lowres male male only malesub monster penis penis out sans sans (undertale) skeleton solo solo male submissive submissive male tied up uke sans undead undertale undertale (series) video games