When you're fucking a girl in the ass and pull out and accidentally give her a pink sock aka prolapse. Then you're all like "damn baby I just pulled your fucking intestines out yo asshole!" So you have to man up and be chivalrous and shit and push that shit back up in her butt. So you punch her prolapse back in for her but your arm gets stuck up inside her anal cavity, causing you to be able to control her basic motor functions, making her your sock puppet.
"Yo dude did you take that chick home last night?"
"Hell yea I did, and let me tell you bro, she was such a freak that she let me sock puppet her."
"You lucky SOB."