When I went to my girlfriend's house for a sleepover date, I found out that she lives with her big-breasted sister, who has a lovely smile! For some reason, this very attractive woman suddenly seduces me, and even though she's right next to me, things suddenly get sexy! I feel Kokoro towards my girlfriend, but that just gets me excited, and I end up having sex with her like crazy! My girlfriend always wears a condom, but she's okay with having sex without a condom! She's even okay with creampies! There's no way I can resist the temptation of a woman like this!