FURVERT!

anthro anthro_on_anthro anthro_penetrated anthro_penetrating anthro_penetrating_anthro ball_growth balls balls_expansion biped comic duo english_text equid equine expansion fellatio fingers freckles_(artist)genital_expansion genital_growth genitals glans growth horse intraspecies male male/male male_penetrated male_penetrating male_penetrating_male mammal medial_ring monochrome muscle_growth oral penetration penile penis penis_expansion sex speech_bubble text vein veiny_penis