Couldn't agree more, I can't honestly wrap my head around how selfish Jooan sounds, does he even realize what he just said? He's willing to give Seojoon what he wants halfheartedly so he can have peace of mind and be comfortable again, without a second thought as to what that's going to do to Seojoon. He puts his needs first and Seojoon's feelings second. He won't even spare him the dignity of walking away when it's clear as day Jooan doesn't even understand how he feels about Seojoon nor how Seojoon feels or what he went through all the years he spent harboring an unrequited love for him. I don't know, there's something that doesn't sit right with me in how he's being all me, me, me right now. Yes, Seojoon definitely dropped something heavy on him, but you would think that having to do something so extreme as to literally run away from him would give him some perspective about how miserable Seojoon must have felt watching his beloved yearn over some other guy he hadn't even seen in years, when he was right in front of him, helping with everything he ever needed.
I find astounding how he could be so blind all along and so insensitive now. "How could you do this to me?", "You should have taken that decision with me.", "come back so you can continue working for me". I want to pluck my hair right off! Not once did he even ask how he was faring.
I don't think Seojoon running away was the right decision, I think it was cowardly and unfair to some extent, but seeing this guy's reaction was to try and keep everything business as usual for his own benefit makes me think it couldn't have happened any other way.
Seojoon needs to get to know a love that doesn't only take and take and take. Get this man a nice man who wants him and treasures him and doesn't take him for granted, Jesus

Honestly this is why I despise the second fiddle trope of harbored love, I know ultimately the second couple are an official coupling, but the Blond Frenchie(Jooan) truly doesn’t deserve Seojoon. Even if you exclude the fact that Joo-an isn’t beholden in returning Seojoon’s feelings he clearly doesn’t “respect” Seojoon beyond what he serves in meeting Joo-an’s immediate needs. I know they’ll end up together regardless of my wants but I genuinely wish the author went the route of giving Seojoon a proper a love interest, and still let Seojoon air out his grievances of being taken for granted. The fact he’ll still end up with Joo-an still ultimately reads as rewarding Joo-an despite his much needed self reflection and maturity growth.