My girlfriend read an article that said, "Sex after a month of abstinence feels amazing!" and imposed a masturbation abstinence rule on me, but from that day on, her younger sister, Mito, started to seduce me. She seems to have a crush on me, and although I usually brush her off, I can't take my eyes off her panties and breasts, which makes me horny from abstinence. No, no, I have a girlfriend... But when my abstinence is about to end, she says, "If you wear a condom, it's not cheating♪" and I lose my reason at the convenient invitation, so I fuck her J-girl body until I finish the whole box! But my pent-up sexual desire can't be contained, so I plunge into the forbidden raw sex!