The subs on Netflix was awful for this scene so I went to another site and took screenshots.

Weiwei was going to buy cake to appease Erxi. She looked at the prices of the cake and asked Nai to lend her the money.

WW: So expensive. Can you lend me the money? I’ll pay you back after I get my salary for the internship.

Note: this is a milestone in their relationship. She found it awkward asking money before from him before (remember the plane ticket?) but now she’s comfortable asking him and unconcerned that others would hear their conversation.

Furthermore, she wasn’t getting paid for her internship, right?

From Ep 18: She told him, “I’m only going to be an intern. I won’t ask for pay.” He answered, “Free labor requires extra caution.”

From Ep 20: She told him, “No, interns don’t get paid. I want to rest on weekends.”

Thus, she was essentially making an empty promise that she’d pay him back after she got her internship wages. There were no wages. She was telling him to pay for the cake. lol.

But he was glad to oblige. Without a word, he opened his wallet and gave her some bills.

WW: Why are you giving me so much?
Nai: The rest is for you to please me with.

This is another “OMG! Did he actually say that?!!” moment. Even the attendant laughed. And look at her facial reaction.

WW: I want this chocolate cake. And please wrap this up for me, too.

On the way out, she handed him the small take-out box.

WW: Here, to please you.
Nai: I don’t like eating cakes.
WW: You’re too hard to please.
Nai: And this is too small.

Now this is a weird moment which viewers missed or ignored. To me, he wasn’t lying when he complained about the cake. He really looked displeased when he took the small cake box from her. 

And that’s strange because he’s usually appreciative of Weiwei’s gifts for him.

Remember this? 

He also grinned when she teased him to drink the “juice of love” she got him.

So why was he complaining about the cake?

Perhaps he was petulant because he got the smaller one and Erxi got the bigger one. It was a case of sour grapes when he said that he didn’t like cakes.

Or perhaps he was expecting her to give him something else OTHER than the cake to please him… Something that wasn’t chosen as an afterthought like the mango pastry.

WW: You’re saying the cake is too small? You don’t understand. You gave me 1000 yuan. If I buy large cakes, I can only buy a few. But if I buy small cakes, I can buy many. (Netflix subs is clearer: I can buy you one many times.) Which one do you want?
Nai: Both of them. (Netflix subs: I want them all.)
WW: How greedy.
Nai: Let’s go.

He leaned in and put his face close to hers.

And I think Weiwei’s answer APPEASED him. See that? He was peeved that he got the smaller and the not-so-cute mango dessert. He gave Weiwei 1000 yuan but she spent only a fraction of it for him while she bought an expensive Sponge Bob chocolate cake for Erxi.

But he was mollified when he discovered her reason for buying a smaller cake for him. She intended, all along, to buy him several more cakes with the leftover money. Now, he was very pleased with that idea. Weiwei was actually THINKING AHEAD and planning to give him more in the future. He wasn’t an afterthought but a forethought.

Of course, he KNEW he was pushing his luck when he said he wanted numerous BIG cakes from her like a greedy kid.

That’s why I found this scene too funny. After all that big talk earlier that he didn’t care if Weiwei flirted with other guys as long as she was with him,

he was annoyed about cake size of all things.

He didn’t like that her best friend, Erxi, was getting the chocolate Sponge Bob cake and he, the boyfriend, received only a small mango tart.

The size differential of the two boxes — and his sulky face — were too obvious.