An Unwanted Erection, purely for the annoyance and anguish of the embarrassed owner.
Commonly shortened to "spont","sponty" or "sponer" (spow-nerr)
"Goeffrey, it has come to my attention that throughout this entire car journey you have been wielding a Spont-On worthy of documentation"
"Oh Isiah, what an embarrassment. I do implore you forgive me my good friend"
"You are forgiven, now enjoy it while it lasts, my friend"