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.
Do-hoon makes Ye-eun attend the shoot afterparty where she drinks too much and gets drunk and dozes off. She awakens all tied up to Do-hoon who's about to torment her and make her submit to him by violating her asshole.
After having sex in the empty classroom during lunch time, the siblings came back to the lecture hall & Taesung started fingering his sister during lecture. He made her so horny that she had them hurry back home to fuck where Haeun grants her brother his wish of fucking her backdoor for the 1st time in her life.