the feeling that you made a terrible mistake by not taking a leak at the office or home or wooded lot that you just left because you are, or know you soon will be, DYING to take a piss and you don't have an acceptable place to do it.
I am experiencing deep PEE-GRET right now; i should have taken a leak at that bar we just left...now i'm stuck in this car in downtown traffic and i'm DYING to go!
The regret felt shortly after leaving one bar on the way to another bar wishing you had gone to the bathroom before you left, because you have to go so bad soon after leaving. May also be obtained from leaving the house to go to a bar.
I totally should have taken a leak before I left. I'm so peegretting it right now.