S: Hey, let’s play that game I like! You say, ‘Hmm, I think I want to buy a new kitten. I’ll go to the pet shop.’
Me: Hmm, I think I’ll go to the pet shop to get a new kitten. Now, where is the pet shop?
M: deep voice The pet shop is over here.
Me: Oh, you’re like my sat nav.
M: I’m not. I’m the shopkeeper.
Me: oh, okay. Aw, look at this baby kitten. She looks lovely. S meowing and cuddling up to me. I’d like to take her home.
M: You have to give me money.
Me: okay, how much?
M: you do not have enough. You only have two pounds and she costs a LOT of money.
S purring and doing various kitten things.
Me: I’ll go to the bank.
M: no. The bad guys went to every bank, and every house, and there is not enough money anywhere. All the banks only have two pounds.
S: Baby kitten forgot! I have money. I don’t need it, you can have it and use it to buy me.
M: No. I need to fix her body.
Me: what’s wrong with her body?
M: she’s a robot. A robot kitten.
Me: I…oh. Uh, are you a robot?
S: I’m not. I’m a kitten.
s and I make various sad faces and plead to the shopkeeper about how we want to be a family. M refuses. It’s all very lighthearted and m and I are laughing. S is staying true to role and does not deviate from being a sad, affectionate cat. Excuse me, a baby kitten.
S: very sad face. Maybe you’ll have to buy a different kitten. Baby kitten is sad because she likes you.
Me: No, I want you to be my kitten.
M: No! You cannot buy her!
S makes claws and a terrifying mean cat face at M.
M bursts into tears.
Curious Adventures 
How delightfully surreal!
It’s the bursting into tears that totally shocked me. Like, we’re engaging in a lighthearted, fun game and BAM.