Boku no Shiawase ≠ Kanojo no Shiawase Extra

One day, Tadashi awakens to his proclivity for cuckoldry.
In his fantasies, he began to fantasize about his wife, Yahiro, being embraced by another man, and this began to interfere with their marriage.
Yahiro's fantasies of her own wife, Yahiro, being held by another man

Yahiro, believing that she was the cause of the fantasy as well, decided to
She decides to engage in cuckold play...

A digest version of the route that was cut from the original game for various reasons.

[From DLsite]