@lmixxo I don't think what you're describing is "whoring out" someone in my opinion. In your specific example of Czech Hunter, never have I thought it an example of it.
What I was referring to is very similar to the first post by @sissyphos. Being whored out not by your own choice, but by the chose of your partner/owner/master. The czech hunter guys choose to do it of their own free will. No one if "forcing" it upon them.
In regards to the porn I saw (a few times). It was obviously a fantasy, and it was so long ago that I hardly remember anything. But, the depiction was as such: A master who had owned a slave has decided to let his slave be used by his friends and strangers. The slave was laying on a sling and the master was beside him (I think) and one after another men would come and fuck him.