A twist on the pearl necklace. It's when a woman squirts all over a man's neck, after having been eaten out while sitting on his face... hence the smell of prawn, and the term "prawn necklace".
"Yo, Ethan, you going to call back that chick from the bar last night? Mercedes, was it?", "Nah, I took her home and she gave me a rancid prawn necklace."
when a man shoots his load around a womans neck area (thus resembling a necklace), but it is done outside during the winter and it freezes on her neck.
It was freezing outside, but I had to get my dick sucked. I left her with a diamondnecklace.
The padlock necklace was first seen in the punk subculture by sid vicious who's girlfriend put a chain and lock around his neck then proceeded to throw away the key as a sign of sid belonging to her. It has then been passed along through communities based on it's overall coolness and trend in style.
Alex:" Oh you have a padlock necklace on?"
Dave:"yeah my girlfriend put it on me. She thought it would be really cool for us to do since we're both into punk rock"