Xbooru - 2010s 2018 2boys 2d 2d (artwork) animated skeleton ass ass grab bed bigger male black socks blue tongue bottom sans bottomwear butt grab digital media (artwork) duo facing another fire elemental grabbing ass grillby grillby (undertale) grillsans imminent sex larger male male male/male male only mari keiyou (artist) mastery position mk-doodles monster monster boy on bed pants partially clothed pink slippers sans sans (undertale) sitting sitting on bed skeleton slippers smaller male socks squeezing ass squeezing butt tongue tongue out topless topless male traditional art traditional media traditional media (artwork) uke sans undead undertale undertale (series) video game character video games yaoi