Xbooru - ... animated skeleton apron big dom big dom small sub bigger dom bigger dom smaller sub bottom sans clothed duo english text glowing eye hair over one eye humanoid humanoid robot imminent spanking mettasans mettaton mettaton ex monster punishment robot humanoid sans sans (undertale) seme mettaton skeleton sketch small sub small sub big dom smaller sub smaller sub bigger dom smirk text top mettaton uke sans undead undertale undertale (series) white background