Rule 34 Dev - 2014 abs all_fours anal anthro avian back ball_gag balls beak bird black_body black_fur black_nose canine claws closed_eyes doggy_style duo erection fangs feathers from_behind fur gag german_shepherd grey_body grey_fur holding kneeling lunalei male male_only mammal marshall_(echofireant) multiple_males muscles nude open_mouth pecs penetration penis pose sex smile talons teeth toe_claws tongue tongue_out wings yaoi|1889669416