Hormones surging, Han-sen's curiosity about sex begins to grow. After much pleading, Tao reluctantly agrees to offer him a private lesson in masturbation and oral sex. When Ze-min returns from overseas and visits Tao’s noodle shop, old memories flood back. Their long-suppressed feelings—Ze-min’s built up from years at sea, and Tao’s stemming from a cold marriage—lead the two pals to give in to their urges, choosing to revisit the flip-fuck days in their youth. While Tao performs oral sex on Ze-min, Han-sen unexpectedly sees everything…