My Brother’s Wife (2018)

Tae-hyeon feels that his marriage life with his wife, Min-ah, feels the same every day and needs a more unique boost of energy. He decided to drive to the suburbs with Min-ah and tries to have car sex to have a different experience, but he is rejected by his stubborn wife, who tells him to return home. At that moment, he happened to receive a written invitation from a couple to film their sex act, but it had the wrong address and was supposedly not for him. However, Tae-hyeon still goes to the place written in the invitation and films Soo-ah and Dong-soo having sex. After that, the couple promises him to be the one having sex with Soo-ah for their next session, so he eagerly waits for the appointment date. But he notices that his wife is acting strangely and realizes that he is in trouble because the promised day happened to be his wife’s birthday.

Where should Tae-hyeon go?