A person who entices (or enables) another knitter/crocheter into buying yarn he or she doesn't need for a project, only to add to their yarn stash. Usually in reference to a pricey/luxury/particularly pretty or desirable yarn. A yarn pusher.
"Mom, this yarn is so pretty! Buy it, I won't tell Dad!"
1)"Oh my God, Cuthbert, do we *have* to watch Star Trek *again*?? It's, like, totally yawnable. Can't we, like, watch a chick flick instead??"
2) "Wowzer, lifting these crates sure is yawnable."