Excuse me, where is the bathroom?

I have been using the same bathrooms as the students for the past several weeks. I always wondered why I never saw another teacher in there but didn’t worry about it. Well, now the bathrooms are getting messier and messier and messier by the day. I think there is a secret, clean bathroom that the foreign teacher does NOT know about.  One that only the Korean teachers know about.  When I find it, I will let you know.