FURVERT!

5:4 all_fours anal anal_masturbation anal_penetration anielde animal_genitalia animal_penis anthro autopenetration canid canine canine_genitalia canine_penis canis disembodied_penis domestic_dog erection genitals german_shepherd herding_dog knot male mammal masturbation non-euclidean_masturbation nude pastoral_dog penetration penile penile_masturbation penis penis_in_own_ass portal portal_(series)portal_autopenetration portal_masturbation portal_ring simple_background solo spacecadet thinking_with_portals valve valve_corporation