Xbooru - 2d 2d (artwork) animated skeleton apron big dom big dom small sub bigger dom bigger dom smaller sub bottom sans clothed crazy eyes crazy smile digital media (artwork) duo english text hair hair over one eye humanoid humanoid robot mettasans mettaton mettaton ex monster onomatopoeia punishment robot robot boy robot humanoid sans sans (undertale) seme mettaton skeleton sketch small sub small sub big dom smaller sub smaller sub bigger dom smirk spanking spanking ass spanking butt sweat text top mettaton uke sans undead undertale undertale (series) video game character video games white background