Twilight Zone 3 Nagakute Amai Yoru

Several months have passed since the protagonist of this game experienced the sexual pleasures and horrors of the mysterious mansion. One day he goes on a date with a girl named Reiko, and his girlfriend Yōko gets jealous. Returning home, the young man begins to think of his behavior and how to improve it, and gradually sinks into a dream that takes him back to the mansion and back to sex.

[From mobygames]