"I... I... Sir..." I started, but my words choked in my throat. My tongue dried. I started imagining. What would it be? Femininity. A body that with every move reminded me of my new situation, that limited me physically.
Master gave me another slap on the chin. Not hard, but enough to make me react.
"...Short, Sir. Very short." I gulped. "Like under five feet. Soft and curvy, maybe a bit chubby. My body would be... would be... uncomfortable, limit me. Little muscle, but limber, so that you could use me in more ways. Disproportionally large hips, big and jiggly breasts. Tiny feet, but modified so that I would have to tip-toe when walking. My face would be very feminine, in a cute and almost child-like way. And maybe..." at this point my voice disappeared again, but my body was on fire with embarassment and arousal. I was literally shaking.
He looked down at me. "Go on," he said.
"This is so embarassing, Sir. Please, don't make me say it." He just gave me a stern look, and I cracked. "A tiny bladder," I whispered, barely audibly. "Barely being able to hold my water. I would be forced to have a toilet nearby at all times, or I'd pee myself."
"I like it," Master said, and started scribbling. I felt the changes come on. My body, currently a healthy and rather well-trained 18-year old girls, started to fill out. I was losing muscle tone, and it felt as if the world around me was growing. I realized it was me shrinking. My breasts started to expand, my butt softening as my hips grew wider. There was a cramp in my legs, and my feet were suddenly stretched out to a tip-toe position. And then a pressure grew in my groin, different from the one from the sexual arousal.
Master looked down at me. "Yes. I do like what I see. I very much like it. You're so soft, so helpless. Now, what to do next. Do you want to be used for my pleasure?" My eyes glanced from his face to his crotch, his erection very visible under the layers of cloth. Very visible, and seemingly much larger. Had he made himself bigger while at it, or was it just my new size playing tricks on me? I started to imagine what he was going to do to me. Which hole would he use first? Would he let me come as well?