When you jerk off into a sock but the bust is so big your sock gets completely coated and becomes crusty. Depending on the bust the sock could become crusty enough to snap like a twig.
Jared: Damn my crusty socks! Another one got crusty enough and snapped!
Dylan: Awwww dude, got a case of crusty sock syndrome? R.I.P.
Jared: Yeah dude, I saved up for like a week and had some high quality porn.