The dialogue in this chapter is genuinely funny, and more importantly, it sounds like two different people talking. Xia Zhen's voice is sharp, self-deprecating, and constantly testing — she fires questions like she's probing for traps. Pei Cheng'an's voice is calm, literal, and devastatingly sincere. The contrast is what makes their conversations work.
Take this exchange:
"What kind of women do you dislike most?"
"Women who aren't kind, who curse constantly, or who have twisted values."
Xia Zhen's internal reaction: "That answer gave Xia Zhen a headache." And then the narration lists why each of those is impossible for her to be. But the dialogue itself is doing something brilliant — it's establishing that Pei Cheng'an's standards are actually about character, not appearance or domesticity. Which makes his earlier "I wouldn't mind" about her gaining weight hit even harder. He's not lowering his standards; his standards were never about that stuff.
The humor comes from the gap between what Xia Zhen expects and what she gets. She's bracing for judgment and gets acceptance. She's looking for a reason to leave and finds none. The dialogue keeps subverting her assumptions, and that's where the comedy lives.
My favorite line has to be Pei Cheng'an's deadpan: "Mm, they are indeed better than you." Said after the kids outperform her in a spar. No sugarcoating, no false encouragement. Just honest observation. And Xia Zhen's response — stomping her foot and kicking him — is perfectly in character. She can't handle the truth, so she attacks the messenger.
The narrative voice also deserves a mention. It's close to Xia Zhen's perspective, but it doesn't get trapped in her head. It occasionally steps back to comment on her behavior with a wry observation, like noting that she exposed her own shortcomings because "she no longer felt the need to protect her image." That's the author winking at us, and it makes the whole thing feel more conversational, less precious.