A Sleeper in Class

Yesterday in class, I was trying my very hardest to teach, but everyone kept laughing and laughing. I discreetly checked my fly to see if it was down. I ran my tongue over my teeth to see if there was something caught in them. I hurried to the bathroom while they were working on an exercise to see if I'd smeared dry erase marker across my face (as I do often enough). But I could not figure out what was going on.
Later, we were having tea together, and I told Jan, the woman I work with, about the constant snickers. She asked one of her ladies (who speak French relatively well) to ask one of my ladies (who don't really understand questions in French at all) why everyone was laughing today.
So one lady asked another in Tachlhit. A discussion ensued.
And then, after it was over, one of my ladies put her head down on her palm and started making snoring noises. She then pointed to one of the ladies in my class who perpetually sleeps.
"They laughed because Aicha was sleeping," one of the ladies said.
"She always sleeps," I replied. "Nothing out of the ordinary."
But they all laughed so hard about the fact that Aicha slept through the whole class, that it almost seemed liked that really was the reason for the laughs. Still, later at home, I took a good long look at myself in the mirror, trying to figure out if there was another reason they still weren't telling me.
And I still don't know. But let's hope for less laughing next time, or I'm going to become paranoid!