I took a deep breath and knocked on the door. Marcus opened it and ushered me inside.

"Just so you know, this room has been built to very precise specifications and is almost totally soundproof. I tested it one day with a couple of very big speakers and you could stand a few feet outside and hear nothing. As you will have noticed the two windows are mirrored on the inside so anyone looking at the room will see their own reflection whereas we can see out quite clearly. You are totally safe from prying eyes in here."

"Thanks, that's very reassuring for someone like me."

"I know, there are a lot of people like you, so it's why I had it built like this. Now, Fiona, if you are going to earn that five hundred you need today we'd better get started. It's going to take a couple of hours at least I would think. First, I need to run a simple pain threshold test on you. No point in going any further if you can't absorb a little pain, is there?" Marcus was smiling but I had an inkling I wasn't going to enjoy this. There was a simple dining chair with an upright back in the middle of the room. Marcus asked me to step behind it and bend over, putting my hands either side of the seat frame.

"You need to hold tight. While you are wearing the skirt and panties I will give you three strokes of the paddle to see how you react. Try to stay still."

Marcus showed me the paddle. It almost made we want to run away but the studio door was locked so we could not be disturbed unexpectedly. The paddle was made of thick leather, about eighteen inches long and three inches wide with a handle at one end.

"Okay, let's see how you do," he said softly.

I took a deep breath and waited. The first swat landed after a few seconds. I felt burning heat right across my bottom, even though the paddle had swatted me through the skirt. I gasped loudly and felt the first tears spring into my eyes. This was not a good start. The second swat landed just above the first and made me grimace as I gripped the sides of the chair as if my life depended on it. The third swat was even harder and landed an inch below the first two.

"Ow," I cried out, still holding on.

"Stay where you are for now. I want to wait a few seconds and see what effect that has had on you." Marcus added. I felt his hands on my skirt, lifting it slowly over my backside so my panties were clearly visible. Not that the G-string covered much up.