Xbooru - 2boys 2d 2d (artwork) anal anal penetration animated skeleton anonymous anonymous male anus ass black socks blue anus blue background blue body blue penis blush blushing bodily fluids bottom sans digital media (artwork) ectobody faceless character faceless male grabbing from behind hooded jacket hoodie legs spread male male/male male only male penetrated male penetrating male penetrating male mkcrown naked stockings penis sans sans (undertale) sex skeleton socks spread legs striped legwear striped stockings striped thighhighs testicles uke sans undertale undertale (series) unknown male video games white body yaoi