4:3 animal_genitalia animal_penis anus backsack balls big_penis blue_eyes blush bridle butt carriage equid equine equine_genitalia equine_penis erection feral genitals half-closed_eyes halter harness hi_res horse horse_carriage_pov looking_at_viewer looking_back male mammal nabesiki narrowed_eyes nude penis presenting presenting_anus presenting_hindquarters smile solo vein veiny_penis