"Had a friend of mine, a friend mind you - not a random stranger, refused to let me use their bathroom when I asked, ESPECIALLY if I was pregnant...I would ride my little bicycle over to the coffee shop - and keep right on riding. That would be the end of the friendship for me."
This sort of thing saddens me, because the situation leads me to consider that such a thing might be justified given emergent circumstances. I agree that it's really unusual to refuse an expected friend access to the facilities, but I've been in the position to understand completely how it can be reasonable. I once had a friend visiting who went into my bathroom, and quite a while later had not returned. I'll spare you the details of what happened in there but when I heard her sobbing through the door and finally convinced her to let me in to help her, the room looked bad enough that I won't describe it at all. To answer gramma dishes's query about how long it could take to freshen up a bathroom this example shows that it could easily have happened quickly and could not be rectified on the spot, and the thing that lets Aoife's friend off the hook for one instance is that there was an alternative and Aoife even mentioned it. So, given all of this together, the condition of the room might have risen past "messy" to "humiliating" and so I'd give a friend a pass for refusing access to the loo without explanation as long as it wasn't repeated.