Do nothing because someone is knocking on the door
From Create Your Own Story
The knock on the door interrupts your activity with Tina. You go and answer it to see your Mom's face, bright and red possibly from her quickie with your step-mom.
"Hello, girls," she says.
"Hi, mom," you sigh, giving her the "you're interrupting me again" face.
"Hello, Mrs. Lesbon," Tina calls out shyly.
"We just want to know if your friend will be joining us for dinner? We just want to have enough food for everyone."
You look at Tina's face for her silent response and tell your Mom that:
