Sun-Young asks her superior Ho-Jun to train her in a Master-Slave BDSM dynamic. His first command is for her to wear a vibrator while walking around. His second command is for her to perform oral sex on him under a table. She keeps his ejaculate in her mouth for the remainder of the workday, which immensely satisfies him. He then rushes her home for an intense sexual encounter.
Yoosun masturbates using a dildo and sticks vibrator up her arse but it's not enough to satisfy her. She gets out of her bed to drink some water to be surprised that Yunho is there too. They exchange compliments and she tells him about her situation, so Yunho feels for her and breaks the line between them once again.