A bottlenecker
A bottlenecker is someone who holds onto a joint like it's the last piece of pizza at a party and won't pass it until they're done even though everyone is dying to take a hit.
Man, Dave is a bottlenecker. He’s been smoking that spliff for 20 minutes and still hasn’t passed it to me.
Why is Steve still holding the joint? He’s a bottlenecker and won’t pass it until he’s done.
That bottlenecker is gonna make me wait until the end of time for my hit.