Her skirt gets lifted

In order to get my books, i usually bend down but with my current state, I crouched instead. So, knees together on the floor, sitting on my feet, I gathered my books. I hugged them to my chest to cover myself somewhat. I was in the process of standing back up when I felt a hand on my skirt! I looked back just in time to see the back of my shirt get lifted above my waist! I squeaked in surprise and jumped away.

"I knew it! You're going commando today!"

My face blushed as I realized who had find out my secret...