Rule 34 Dev - 2d 3boys all_fours anal anal_sex black_hair blowjob blue_cum bodily_fluids cum cum_in_ass cum_in_mouth cum_inside cum_on_ass cum_on_face dark_background doggy_style humanoid_robot male mettaton mettaton_ex orange_cum papyrus purple_eyes robot sans undertale undertale_(series)|7906134296