alicorn animal_genitalia anus backsack balls balls_deep blue_fur blue_hair blue_penis clenched_teeth closed_eyes cutie_mark duo equine erection fan_character female friendship_is_magic from_behind fur hair half-closed_eyes horn horsecock inside internal jcoshooves looking_back male mammal my_little_pony necklace open_mouth penetration penis princess_luna_(mlp) pussy sex shower straight teeth tongue two_tone_hair unicorn vaginal_penetration vein wet wings