"Does touching with your hand not count as cheating?" In a three-night hotel, I was masturbated 19 times by my girlfriend's younger sister, the little devil, and then she took me away. (Ono Rikka MIDA-106)

The girls I used to like (I don't have much dating experience) were usually attracted to their inner qualities, not their looks. However, my current girlfriend's younger sister is the cutest girl I've ever met, and she's really bothering me. She's always secretly trying to seduce me… Although I really want to avoid this, she's just too cute, and I can't help but want her. Her sister, Rika, says that masturbation isn't cheating and strongly tries to sell me this idea. Even though I know it's wrong for my girlfriend, I still end up ejaculating because of Rika's masturbation—it's a terrible yet incredibly pleasurable experience…