When your balls are semi-sweaty, so that your scrotum sticks to the inside of your leg. Usually you can tell a man with scrotum stick by the way he's walking (trying to unstick his sack from his leg by walking in a very open legged motion -- similar to stradle strut for women but for very different reasons) or pulling at his sack so as to relieve the stickiness.
Sean: "What are you doing, streching your hammies?"

Mike: "No, I've got some nasty scrotum stick I'm trying to alleviate."

***

"Mike's scrotum stick was even worse because he shaved his balls."
by Severance June 27, 2006
Get the scrotum stick mug.