It's 1960 and Bobby goes to pick up his date, Peggy Sue.
Peggy Sue's father answers the door and invites him in. He asks Bobby what they're planning to do on the date. Bobby politely responds that they'll probably just go to the malt shop or to a drive-in movie. The father suggests, "Why don't you kids go out and screw? I hear all of the kids are doing it."
Bobby is shocked. "Excuse me, sir?"
"Oh yeah, Peggy Sue really loves to screw. She'll screw all night if we let her."
Peggy Sue comes downstairs and announces that she's ready to go.
About 20 minutes later, a thoroughly disheveled Peggy Sue rushes back into the house, slams the door behind her, and screams at her father,
"Daddy! It’s the TWIST! It's called the TWIST!"