After a date with his girlfriend who has a 5 PM cutoff, he engages in an "internal ejaculation sex" session with "her mother" to create a "girlfriend's younger sister." (Sugisaki Honoka ROE-565)

I decided to visit my girlfriend's house, a place with a 5 PM curfew and an incredibly rigid atmosphere, like it belonged to a different era. The visit itself wasn't the problem, but later I arranged to speak alone with my girlfriend's mother, Ms. Honoka, whom I'd met there… Unexpectedly, she said, "For my daughter's sake, please break up with her." In a moment of impulse, I impulsively pushed Ms. Honoka onto the bed. Unlike my girlfriend, facing Ms. Honoka, who exuded a mature woman's allure, I felt a complex mix of anger and lust, and I couldn't help but ejaculate inside her…! From that day on, we became accomplices, repeatedly having secret rendezvous after parting ways with my 5 PM curfew girlfriend…