rule 34 2017 anal anal sex animal genitalia animal penis anthro anthro on anthro anus automail balls black hair black penis blonde hair blush cheetah closed eyes cybernetics dragon duo equine penis erection eyewear feline fur glasses green eyes hair hand behind head hand on chest horn cock hybrid long hair machine male male penetrating mammal mastery position mikhail alkaev muscular nipples nude penetration penis pig artist prosthetic scalie sex simple background sitting size difference smile spots spotted fur straddling yaoi yellow fur 2443893