All His Air, How to Please Him

Master took the slip knot tied leather strap from around my wrists, opened it into a wide loop and told me to lean my head down to it.

A clench of fear/excitement passed through me as I obeyed.  He slipped the strap around my neck and pulled it up.

"Is that tight?" he asked.

I nodded, "Yes, Master".   I could still talk.

He tightened it in a few notches.

"Is that tighter now?"   I nodded again, not speaking this time.

He tightened it again.  He might have said some else, but I'm not sure.  
Now all my attention was focused at my throat.
A primal fear of dying was coursing through my brain cells even as my mind told of complete trust in his control and his desire not to harm me.

After I don't know how long, he released the strap, and as he did so, he commanded me to orgasm.  I convulsed in desperate pleasure.  He tightened it again.  

 He was holding the end of the strap up above my head and a little to my left.   Again he commanded me to cum while releasing the pressure on my neck.  Almost immediately it tightened again.   Then one more time again, but this time he loosened it completely, released the strap and switched his grip, using one hand to pinch my nose shut and the other to cover my mouth.  I had very little in the way of calm reserves left now and it seemed only a few seconds before I was shaking my head and trying to get away, to get a breath.

He asked "Is this better?" but it must have been rhetorical because there was no way I could answer with his hands covering me.  I just kept shaking my head.

 When he finally released me I collapsed against him with something like a sob mingled in my orgasmic moan.  

After a few moments of my deep breathing, he asked:
 
"Now that I've given you ALL the pleasures, what can you do to please me?"