The proper way of drinking sake on a woman is by pouring it on her boobs and vagina. Meanwhile, the way to drink to it on a man is to pour the sake on the penis and suck on it.
Wang-Gu jerks off to relieve himself while Woo-Hee is sleeping in the same bed. Woo-Hee gets aroused listening to him. Woo-Hee catches her husband kissing a co-worker.