Pee-panic
The panicked need to pee combined with the sudden psychological urgentness that seems to come when you’re finally at the urinal or toilet and get stuck on a zipper or can’t find the hole in your boxers. When you’ve waited for an hour and almost piss yourself at the last second.
I finally got to the front of the long bathroom line at the concert and had a pee-panic when I couldn’t get my dick out of my pants.