Eh? it's simple? Seo is getting jealous over small touches and even Natori meeting other guys while he touches, kisses, flirts and fucks many other people daily. And he doesn't think "I can't be so selfish, I need to respect his personal area, he's free to meet whoever he wants and do whatever he wants" as Natori thinks. Only the blind wouldn't see that Seo's work isn't really okay for Natori, he no longer enjoys seeing Seo do all the lovely stuff he does to him do with other people but he ignores his feelings because he wants to respect his partner and doesn't want to bother him. He's not voicing it all properly in order not to hurt Seo and that's okay, his choice. But that's not healthy nor equal. That's why I want to see Natori do the same kind of job for Seo to see what it means and what Natori has to feel if Seo doesn't even bother to think about it himself. Of course you can disagree, that's just my opinion
They literally talked it out this chapter and the chapter before. Feel free to read again, that's prevent you from inventing things.
And don't compare Seo's jealousy with Natori's jealousy. Seo was jealous because someone was touching his lover in a private setting and could have been cheating if it wasn't a sexual assault. That's completely different from Natori being jealousy due to Seo doing his job, which involves having sex with other people (all fake).
now i want natori to become a pornstar as well ╮( ̄▽ ̄)╭ would love to see them being equal