I heard a woman saying this on some radio channel..

"How do you know I was'nt slapping my face around"

What does this mean ??
Hard to say without the context. What were they discussing?
Students: We have free audio pronunciation exercises.
The lady said to the other lady that she must be enjoying the past 2 days she did'nt show up in some club or at work. The other lady said something like , how do you know that I was enjoying and was'nt slapping my face around............
Sorry, I still can't think of what it might mean.