The bathrooms at work are locked. If you give the key to a customer more times than not it A) gets left in the bathroom or B) comes back wet. So it’s easier and less disgusting to just let customers in using your own key (unless the customer is a complete dick, then the bathroom is broken):
Guy: You guys have a bathroom?
Me: Yeah, this….
Guy: (interrupting) Thank God, I drove up from Barnegat and jesus, I gotta go.
Me: (walking towards the bathroom)…Yeah,…uh…
Guy:..and I had a big coffee so ya know…
Me: Look man, I’m sorry and I don’t want to be rude but I don’t really want to hear about how bad you have to go to the bathroom.
Guy: Oh..uh I just wanted to tell you so you wouldn’t think I was faking.
Me: I don’t care if you’re faking or not
Guy: Yeah, but…I’m not…I really have to go.
Me: (I open the bathroom door) …light’s on the left
Guy: (as door is closing) I really do.