When, at a dance, a party, or at school, a boy of a group finds the nearest fat/chubby girl and proceeds to place his finger in a stabbing jesture on her back/shoulder.
The boy may run back to his group so when the girl turns around, he may point and laugh at one of his other friends, turning the blame on him.
Very damaging to the girl's self esteem unless they can take a joke.
Chubby Girl: "I was chillin' with Diana and Joe at homecoming when some random dude fat-girl-poked me!! *cries*"
Chubby Girl's Friend: "What?? Who was it??"
Chubby Girl: "I don't know! He ran back into that group of guys who were just laughing!! *points and cries more*"