When I returned to my wife's parents' house, my beautiful sister-in-law was waiting for me. Forcibly, boldly, and persistently seducing me...Even though I was confused, the dam of reason was on the verge of bursting. Even though I know I shouldn't, my heart is shaken by the charm that my wife doesn't have, and I end up having sex with her! And by the time the reason for her obsession with him became clear and she was horrified, she was already charmed by her sister-in-law to the point that it was too late.