A Cock Scarf is most easily described as someone you can't get rid of, basicallly someone who is always trying to be around you as if they are attempting to keep your cock warm as a scarf would.
1. "holy shit, Chris keeps calling me man, I told him I'm trying to lay low tonight, what a Cock Scarf!"
2. "Claire is such a dumb bitch man, she thinks she has to be around me 24/7, its like he' trying to keep my cock warm like a regular Cock Scarf!"