This is the "Fatty" episode. I feel like these 9 episodes are about how Fatty, who initially had never had sex or even touched a woman's breasts, used the only opportunity So-eun gave him to penetrate her gentle heart. Fatty is like someone who's never satisfied, from a chubby kid who was bullied to bullying So-eun in bed. He takes advantage of her pity. For example, in episode 61, So-eun helps Fatty solve his bullying problem by taking him away from the situation, to a hotel, so he can take nude photos of her, simulating a scenario where they have sex and So-eun is showering. So-eun asks Fatty to take pictures of her, and when she sees the photos, he takes advantage of the situation by photographing her genitals, causing her to scold him. Fatty sends the photos to the bullies, who don't believe them. So-eun asks him to take new photos, this time from the front. Fatty takes this opportunity to touch her breasts, claiming it's to make it more realistic to deceive the bullies. After that, Fatty gives up on deceiving the bullies about having a girlfriend and tells them to stop what they're doing.  He then asked So-eun to touch his breasts instead, which of course she refused. The chubby guy switched roles from victim to bully by saying he wouldn't go to the gym to help her promote it. So-eun eventually gave in and let him touch them. He then took advantage of this for the fourth time, not only touching but also sucking her breasts without asking. He continued to ask for permission, progressing from simply taking pictures to grabbing and sucking her breasts, and eventually tricking her into letting him see and lick her vagina without asking – it's impossible to remember how many times he did this. Finally, out of kindness, she allowed him to have sex with her so her boyfriend could hear them. They used a condom, and she ejaculated. He seized the opportunity, grabbed another condom, tore it open, put it on his penis, and immediately had sex with So-eun without asking. He tried every position he could find until he was satisfied. He wanted more and begged her, but she said she didn't have another condom. He offered to ejaculate outside, but she refused, so she gave him oral sex for a while. Ultimately, this chubby guy's bad habit of doing things without asking others is evident.  He forced himself on her, inserting his unprotected penis into her, having sex with her in various positions in a frenzied manner, until finally he ejaculated inside her. He said he would ejaculate outside, but he did. He transformed from victim to hunter. The fat guy's problem became So-eun's problem. Weeks passed, and he went to the gym and had sex with So-eun in the bathroom several times, until he started to think he was her boyfriend, which displeased her. Clearly, this is how the innocent fat guy, a mere scapegoat, transforms into a wolf of prey. These are my favorite episodes, especially the one where So-eun is taken advantage of without being told what's going to happen.

Soeun 60-68 is the best