anal anal_penetration animal_genitalia animal_penis bestiality bodily_fluids cum cum_in_ass cum_inside duo equid equine equine_genitalia equine_penis erection feral feral_penetrating feral_penetrating_human genital_fluids genitals horse human human_on_feral human_penetrated interspecies larger_male male male/male male_on_feral male_penetrated male_penetrating male_penetrating_male mammal nude penetration penis power_bottom saliva sex size_difference smaller_male sweat tongue tongue_out unknown_artist