The fact that Aaron deliberately choose that blonde actor for the role knowing very well he wouldn't be able to pull it off, he made yuujin practice the script at home under the guise of "help me practice my dialogs" and now Yujin is about to debute as an actor.
My man Aaron is completely head over heels for Yuujin. He has lost his mind. I can not believe he planned all this just make sure debute yuujin as an actor.
For people who are asking why Aaron is always on the edge with Yuujin... well it's cause Yuujin is hoe, the moment Aaron takes his eyes off of yuujin... yuujin is gonna hop on some other dick. And since their relationship is binded by contract technically Aaron can't say anything about whom yuujin actually wanna fuck. So Aaron's insecurities are basically manifesting into such rough sex and all those ass slapping. He wants yuujin to be sexually satisfied with himself so he won’t run off with others.
At the last panel... Aaron went from "hehe" to "not hehe".