The playdate veered off into Barbie-(and Disney princess and Aladdin and Ken and Violet from The Incredibles)-storytelling-land, with most of the lines each girl spoke prompted by the other (Okay, pretend he says... Now pretend she says...):
There were two sisters who liked the same boy, but he only liked one sister and wanted to go to prom with her. The other sister confronted him, demanding that he tell her the truth: "I'll be all right. It'll just hurt me." So he told her he didn't like her, and went over to her sister.
Then she put on a different dress and he said, "Okay. Mind. CHANGED." Then he pushed her over and took off all his clothes, except he kept his underwear on ["Don't really take off his pants! They're too hard to put back on!" "I won't, I won't"].
At this turn of events, she said, "Slap out of it!" Then the sisters' mother showed up and told the sister with the imaginarily-pantsless boy that she was too young to have a boyfriend, but that the other sister was too old not to have a boyfriend and needed to get one before they went out on their mission. And the older sister rolled her eyes and sighed, "But why do I HAVE to? Why can't we just go on the mission?"
"I've never seen you in your mission clothes before."
"Do you like them? Do they make me look ugly?"
"No, they make you look scary."
"OH! I can't believe it!" And then Violet stormed away. Then Ken started shaking her sister's hand and they said, "Hello, how do you do, how do you do?" And then Violet returned and wailed, "Oh, how dare you! I'm going to beat you up!"
And then she picked him up so she could bring him to his house. And then he fell really, really in love with another girl. He fell in love mostly, most of all, with Clawdeen from Monster High.
"I'm sorry," she told him, "but I don't like you the way you like me. ["Pretend she already has a boyfriend."] I already have a boyfriend. ["Pretend he starts to dance with someone else."] All right! All right! I'll dance with you!"
["Pretend she fainted. Now pretend he doesn't really like her shoes."] "I don't really like the shoes. But I do like this dress."
And then they danced, but he made her pass out because her foot was very injured. "M'leg's broken, m'leg's broh-ken," she cried out in a weirdly decadent-wealthy-lady-in-a-Regency-romance drawl.
Then Violet became a nurse, and wore Rapunzel's dress as her nurse uniform for purposes of leg-mending.
Then they abandoned everyone in a heap on the couch and ran back to the bedroom to draw in Matilda's scrapbook and laugh themselves into helpless screams of glee.