Michael is expecting the apology, and is just as ready to tell Lee all the reasons the world can fuck itself as she is to say she's sorry, but it never comes. It's nice, to hear nothing there. He spends a moment admiring her.
Rich is not someone Michael likes as a person, but he is Lee's pseudo-boss-friend-guy and Michael generally treats their interactions as work-related. When Lee has to do things like attend social events without him and go to the Chelsea at random hours, he doesn't see a reason to get bent out of shape. He's unavailable far more often than Lee is, after all.
That's not to say he hasn't quickly grown accustomed to having Lee around, though. He gets restless and nervous when he's alone in his apartment, and often ends up going out and walking for as long as he can rather than sit there by himself. It's not that they're always talking or kissing or interacting when they're together; it's that she is Lee. Just having her asleep in the next room makes things stop jangling so loudly in his ears.
But it's okay.
“It's okay. I understand that people need to see how great you are with their own two eyes because they literally won't believe it otherwise.” A matter of fact.