1. The act of holding others back, with no intention of gaining from restraining their peers.
2. Intentionally ruining something for someone simply for the joy of watching them suffer.
The word originates from crabs in a pot cooking. When some of the crabs try to escape from being cooked, one crab would grab the others, preventing them from escaping. That crab is called the crabstick.
Oh man, Shorty is such a crabstick!!
Shorty sucks you in like a dirty little crabstick!