"You've done well pet, diligently soaking these panties for a fortnight, masturbating in them as ordered. You can continue to do the same in your new ones. Is that clear?"
"Ahh...for how long?" I asked, blushing bright red.
"I'll decide when you'll be allowed to change. Maybe only if you're a good girl~"
"Yes, Master," I said, moaning.
Commission from 
Art work by me