FURVERT!

against_surface against_wall anthro anthro_penetrated avian beak big_penis biped bird blue_eyes claydust duo female female_on_human female_penetrated from_behind_position genitals hi_res hirundinid human human_on_anthro human_penetrating human_penetrating_anthro interspecies larger_human larger_male male male/female male_on_anthro male_penetrating male_penetrating_female mammal mostly_nude oscine passerine penetration penile penile_penetration penis penis_in_vagina sega sex size_difference smaller_anthro smaller_female smaller_penetrated sonic_riders sonic_the_hedgehog_(series)swallow_(bird)vaginal vaginal_penetration vein veiny_penis vulva wave_the_swallow