Wait I didn't understand, why muyeol didn't touch his manager?

It is yet to be revealed but my guess is that he doesn't really thought about it

If we follow Chani's train of thoughts, a 'normal and decent' person, like Philip (manager) shouldn't be touched by a 'slut' (Muyeol). They know better than be involved with a 'naive and innocent' person because it would bring trouble for them if they start to get serious. Maybe Chani's talking from experience lol