after_sex anthro anus backsack balls big_balls big_penis black_hair black_penis border_collie butt canine cum cum_in_ass cum_inside dog filut gaping gaping_anus gay green_eyes hair hyper hyper_penis kimbyfox looking_at_viewer looking_back male mammal penis presenting presenting_hindquarters revadiehard simple_background solo spread_anus spreading tongue tongue_out uncut vein veiny_penis