When the man ejaculates before the woman cums, the sex begins all over again and the same goes for when he ejaculates on time and the sex repeats. His techniques get better, but he can't help but ejaculate prematurely and everything is back to square one... endless sex. The man has sex with two women everyday and is trapped in a loophole of sex. He doesn't have a choice. The man can only get out of it if he doesn't ejaculate. However, he feels horny again almost right away and he ejaculates too soon, once again... He has to get out!

Hyeong-woo is forced to be quarantined with her sisters-in-law for 21 days due to the new virus. Hyeong-woo, who remains with his sister-in-law is shaken by the temptation of prohibition. Eventually, the virus spreads and becomes the beginning of human extinction. However, rumors are circulating that sharing forbidden love can amplify the energy and defeat the new virus, which they cannot help but believe. Their own sex, which began like that, makes them forget even the fear of the virus and makes them unable to break up.

Sin-wook and Dong-soo have been friends since they were kids. Sin-wook and his wife swap partners with Dong-soo and his wife. They start playing Strip Go Stop and the game gets serious. The four of them have sex, but they end up falling for each others' wives and husbands and even meet in secret. One day, when their sex life reaches its peak, Sin-wook's wife, Yeon-hee, gets pregnant, not knowing whose baby it is. Her relationship with Sin-wook is on thin ice and then the baby is born. They do a DNA test to find out who the father is.