MIDE-339 — My Girlfriend's Sister Secretly Seduces Me Minami Hatsukawa

When I went to my girlfriend's house, her sister, who is very naughty, cute and bold, kept seducing me one after another! I like her, but when my sister seduces me, I can't help but feel guilty, but I just let her do what she wants! She has better technique than my girlfriend, and it feels so good that we just keep fucking each other! I don't want to get found out, but I'm so excited about this relationship that I can't stop!