rule 34 1610 2boys animal genitalia animal penis anthro anthro on anthro black eyebrows black hair black nose black penis black tail bodily fluids brown body brown ears brown fur brown head tuft brown tail chest tuft cum duo english text equid equine equine penis erection eyebrows fur gay genitals gradient penis green underwear grey body grey ears grey fur hair head tuft lutrine male malemale male only mammal medial ring mustelid penis pink penis red underwear shoulder tuft signature simple background sweat tan body tan eyebrows tan fur tan inner ear tan tail text thought bubble tuft underwear vein veiny penis widescreen yaoi yookie 5973961