2boys, black_pants, blonde_hair, blue_scales, city, city_lights, closed_eyes, completely_nude, curtains, diego_brando, facing_away, facing_to_the_side, fins, frilled_sleeves, frills, from_behind, full_body, head_fins, indoors, interspecies, johnny_joestar, jojo_no_kimyou_na_bouken, leaning_on_person, long_hair, long_sleeves, male_focus, merman, monster_boy, monsterification, multiple_boys, no_shirt, nude, open_clothes, pants, puffy_long_sleeves, puffy_sleeves, riqingfan, sitting, steel_ball_run, window, windowsill, yaoi