Back-hand to the balls
I am the bulls donkey slave.
A trumpet sounds and I enter the room, crawling on all fours wearing a donkey outfit and He rides in on me wearing a crown, for he is the KING.
It is a sex party of several, or many, girls - all of them, every single one of them, are for the bull; not one for me.
I supply the beer and wine, the crackers and cheese, the grapes, and other food. And I bring several boxes of condoms. Everyone knows I paid for it - yet do not get to have anything.
My duties are simple, keep the food coming and put condoms onto the bull, replacing them as he uses them.
If this isn't humiliating enough, whenever I get a hard-on I am ordered to stand before the girls. They laugh and laugh, and hysterically so when the bull comes up to me. I plead, "No, please master - not the balls", but to no avail; the bull gives me a back-hand to the balls to make me limp for I am not allowed a hard-on while he is fucking. The girls LOVE it, and make a point of jiggling their tits, and shoving their pussy and ass in my face, so that I'll get hard again - and then smacked in the balls again, and again, and again as they fuck the bull over and over in front of me.
When it's all over I get the condoms I paid for that the bull used as my reward; and I come running to do it again the next time the bull gets a stable/harem together for a fuck fest.