I love my girlfriend, but after meeting her adult younger sister Eimi, I become addicted to having sex with her. I know we have crossed a line, yet I can no longer control myself. I go an entire month without masturbation or sex, saving up an enormous load so I can fuck Eimi. Once my abstinence ends, Eimi and I use the few days my girlfriend is away to have sex from morning to night, and I keep creampieing her until she becomes pregnant.