Stuck on frwy due to accident ahead. Let others use toilet?

Dog Folks wrote:
No offense at all, in any way, shape, or form is intended but;

Why does everyone here want to offer an explanation?

A smile and a simple "no" should be enough.

Is it required to be polite?

This is a common thing with people - to justify a response by providing reasons, instead a simple "I'm sorry, but no". The problem with providing reasons is that many people will argue with you that your reasons aren't good enough. Sometimes "because I said so" is still the best reason. :)