When you're holding it in
, there will often be about 5-10 minutes where you really have to go, followed by another 5-10 minutes where the feeling seems to go away. This feeling is the calm before the storm, and you should take advantage of it and find a bathroom ASAP. Because when the feeling of having to go comes back, it's gonna be 10x worse.
Bob: Man, I really gotta go.
Joe: Okay then, I'll pull into this gas station.
Bob: Never mind, it's going away. I think I can hold it in longer.
Joe: No you can't, that's the calm before the storm. I don't want you pissing yourself in my car.