When you are fucking someone anally who is wearing a necklace you grab it and pull back as hard as you can making them gag and gasp for breathe as you pound them from behind. Sometimes resulting in a pink sock.
Josh: "Haha me and Jen were doing it doggy style last night when i noticed she was wearing her necklace, So i grabbed and yanked back"
Zack: "Haha nice classic jewelin right there."
Josh: "ya except she tighted up her ass when i did it and i pulled out... she got the pink sock it was nasty"