A bottlenecker 

While smoking Marijuana communally among a group, a bottlenecker is an individual, when passed, keeps smoking the joint/spliff much longer than they should resulting in others frequently reminding them to pass the joint/spliff to the next recipient.

The individual effectively creates a bottle neck in the flow of weed being consumed within the group.

Dude you've become a bottlenecker these days - you never pass the spliff!

A bottlenecker by howiquitweed November 2, 2011