Titty twisters? I guess that since I was a guy we called them Tee-Tee Twisters (I was like 5 or 6 at the time though) and we'd do it to joke around, but if we were really mad we'd do it maliciously, I made my older brother REALLY mad one time because he was being an asshole while I was in a bad mood so I grabbed and twisted as hard as I could, suffice enough to say that he got his revenge real fast though.