rule 34 anthro brown body brown fur comic duo erection featureless chest female female penetrated from front position fur genitals grey body grey fur hi res lirkov lying male malefemale male penetrating male penetrating female mammal marker artwork missionary position mouse murid murine nude on back open mouth penetration penile penile penetration penis penis in pussy pussy rodent sciurid sex traditional media artwork tree squirrel vaginal penetration vaginal penetration 7487172