"Huh, I never figured he was actually afraid of her at all; my take is almost the opposite - the archetype of the mother who everyone is "afraid" of in a performative way while actually she has no real power and no influence on anything or anyone. She just gets to play at terrorising her household as if that somehow made up for her actual powerlessness."

In this chapter already "The change in his posture was like night and day. He went from sitting boldly on his swivel chair, looking powerful and domineering, to shrinking into a ball." And she can't even see him, he's clearly not performing his body language for her on the phone. And then in the upcoming chapter he has so, so many unpleasant feelings about talking to her, and yeah, there she can see him, but I don't think "The tension in his back was faintly visible through his shirt." is something he's performing either. (And also actually none of this matters because 'my kid acts scared around me and that's not just fine, it's good and validating' is just as vile.)

But it's best for me and everyone else if I just don't talk about his parents, so I'll just stop here. :)