When someone is to scared to approach a girl so they wait for someone else
(usually another guy) to make a move and once the other guy starts the conversation they casually join by leeching off the other guy.
Usually Sean in desperate crowds.
Bro I donât go to Ben Yehuda ! Way to much leech effect I canât do it , I got cockblocked today I was talking to this sem girl and avi did the leech effect and she walked away mid sentence