Milking fantasy

This is a newly discovered fantasy of mine.

It starts off as an edging session where I'm tied up and edged for an extended period of time. When I can't take it anymore and I'm given permission to cum, I release my load and I ask to be untied. I am told that I will not be untied until I have been milked dry. I am unable to do anything as my sensitive cock is stimulated and edged again and again. I beg for it to stop but it continues for hours and only stops when my captor is satisfied that my cock has been milked dry.