Mind Wandering

I'm not sure whether it's a slave's place to think this let alone write it  but our relationship is such that I believe it will be read with interest, another facet of the slave's mind, rather than it being seen as impudence. I don't fancy the 48 hours of continual punishment that would result.
However, I have of late been rather taken with the thought of what it would be like to fuck my Master. In those odd moments that I have when not otherwise occupied I muse about the feeling I'd get and what he might think of it.
 My reason for apprehension is obvious. It's the last thing a slave should be thinking. Up to now my only way of getting the better of him has been to refuse to plead when being beaten. He sometimes gives me the opportunity part way through a lashing to plead for submission (I'm not sure if it would have any effect anyway) and inside my head I'm shouting "NO! Sod off!" whilst my mouth, if not gagged, is saying "Thankyou Master, I will when I can't take any more." It's my rather pathetic way of making him work harder for the result. Up to now that is.
I have this vision in my head. He's sleeping on his front. It's a warm summer afternoon and there's only a white sheet covering him. I'm naked and standing at the foot of the bed. I slowly gather up the sheet and gradually uncover him until his body is visible up to his waist. Carefully I kneel, first one knee then the other, on the bed between his legs making sure he is not disturbed. I lean forward so that my face is close to his arse. With my hands on his cheeks I almost imperceptibly push my tongue between them, slowly caressing the crack until the tip finds his hole and I lick around the puckered skin of the opening. As I pull the fleshy cheeks further apart my face pushes forward and my tongue enters his body. I now have that smell of sex and his intimate body parts surging through me which immediately makes my semi hard cock rigid with anticipation. I press my tongue further and further backing off only to catch a breath. The area is wet with my licking and tongue play as I tickle him from under his balls to the point where his spine seems to end. He breathes deeply as if having a rather exotic dream, which is what I have intended.
My one hand is playing softly with his back, my tongue is enjoying his hole and my other hand is wanking me slowly until my cock can no longer wait. I sit up carefully, lean forward until I can feel the resistance of his entry against my precum covered organ. A firm but smooth movement and I'm in. My cock is hot with the grasp he has on it. I feel an tremendous sensation of both power and love, respect and domination. I need him   like this. There's an almost electrical charge pulsing from my cock head to my stomach down my thighs and into my legs. The rocking gets more urgent as I need to cum, I badly need to cum. I have this power now, he is under me and I dominate. Then it happens. There is a tightness inside which grabs my gut then explodes out through the most sensitive part of me releasing all the feelings I have had inside my head.

I stop rocking, withdraw in a slow careful movement and sit there wondering what I have done. He appears to be asleep. Getting off his bed I replace the sheet and tiptoe out of the room. In the kitchen I prepare his afternoon tea which I will serve him in bed this afternoon.

It takes about 20 minutes  to get everything ready. I put on my leather shorts and, as I already have the slave collar locked in place, I'm fully dressed. I take the tray up to his room, knock gently and enter. As I step inside I see the bed is now empty so I approach the bedside table thinking Sir is in the bathroom. I then hear the bedroom door swing closed behind me. Turning I find he is right there fully dressed in his leathers, gleaming boots and with six feet of bull whip which he slowly draws through his gloved hands. It gives me a start and I almost drop the tray but he's smiling and tells me to put it down on the table I was originally aiming for. I do this, turn and stand waiting for whatever is to come next. Inside my leather shorts I can feel my cock twitch and begin to erect, simply looking at him like that does it for me. My brain tells me to be careful, it's all too relaxed, and I have more than a sneaking suspicion that my conscience does well to be pricking.
"Go to the bed, see the manacles there?
"Yes Sir."
"Put them on your wrists behind your back."
"Sir."
It's not difficult, they are heavy steel wrist bands joined by about twelve inches of sturdy chain and as such I can put one on then pull the other one round and fix them as ordered. They have locking bolts to secure them which I can do with my fingers. I stand facing him, my wrists secured in shiny metal just behind my thighs and my stomach churning.
"I had quite a vivid dream this afternoon boi."
"Sir."
"Yes, not unpleasant but a bit unexpected."
I look at his feet.
"I could do with some help in understanding parts of it."
I nod.
"Any ideas?"
I remain silent and stare at the floor in front of me.
The bull whip has lashed across my chest before I even see his arm move. I yell in surprise as much as pain and buckle slightly.
"Did I say you could speak?"
"No Sir," gasping. The chain catches my thigh as I instinctively pull my wrists up to protect myself.
"Did I say you could move?"
"No Sir."
"Then don't!"
I look at him in the face. I spread my feet slightly and wait for the next crack of the whip. If I see it coming I can at least prepare. It comes. He's still got a smile at the edges of his mouth and the whip isn't as hard as it could be but this time it encircles my arms embedding it's tail under my left arm pit. That's a killer and I have great trouble stifling a yell through clenched teeth. I bend forward slightly then straighten up. I will not crumple!
"Still no ideas? I thought you may have one or two by now."
"Sir."
He swings his arm back and the plaited leather tail parts the still air of the room to burn its way into my chest. I see red wheals where the first two strokes bit into me. With a good lashing movement the plaits can open slightly before they land then compress again sometimes catching tiny edges of skin and pulling them away. He does not use the whip that hard today. There is no blood, just a burning pain.
I stand there. He knows, and he knows I know. Cat and mouse time. I have nothing to lose.
"Your tea Sir. It will get cold."
Crack.
And another. Five from a bull whip at medium strength doesn't sound exactly life threatening but having to stand still and take it, almost unbound, is not easy.
"Thank you boi. I'd almost forgotten. Stand still while I pour."