Not quite that, and not humiliating, but a huge turn on! My wife enjoys performing for me when we hook up with a bull, and would impale herself cowgirl style on his cock. He's sitting back, she's facing me and filling herself with him, sometimes, in her ass, but most times, her pussy. Then, she asks me to eat her as he fucks her. She spread her legs over his thighs. I can see his cock, wet from her juices, pumping himself in her. Her clit is engorged as she rubs it and I can't resist! I've had my tongue on his shaft, tasting her. Even took it in my mouth as it pulled out of her. But, she pushes it back in and forces my head against her until they come.
A few times, we were eating each other at a party and she would let someone fuck her. I watched his cock push onto her wet pussy. It rubbed my face as I kept tonguing her clit. Once, he pulled out of her and came on my face and chest. She kept sucking me and I came in incredible spurts at how fucking hot it was!