Say What??

So today I showed up for my djembe lesson, and my instructor greeted me with, "Hi! You can go ahead and use the bathroom first before we start-- if you don't mind."

I didn't need to go to the bathroom. I am fifty years old. I think I know when I need to use the bathroom! My drum lesson is only a half-hour long! This was strange for him to insist I use the bathroom! Firmly, but politely I responded, "No thank-you, I already went before I came." (not that it's any of your damned business I thought to myself)

His eyebrows furrowed and there was a looong pause before he said, ". . .NO. . .I need to use the bathroom. . .IF you don't mind?"

"Oh." I said sheepishly, then started laughing like a crazy woman when it hit me how funny the whole misunderstanding was. I was still laughing when he came back from the bathroom. I'm quite sure he thinks I'm a nut.