Did that once with a Finnish girl while her husband watched. It was very kinky. It was good that her husband was there as I think it gave her a sense of security.
It was also very different from what you see on porn films. That seems to be very much as CL described - men using a woman for their own sexual gratification.
I didn't know any of the men involved, and I have to admit, I did need a little alcohol to go along with it, but it was a lot of fun and the woman was treated very respectfully and she enjoyed being the centre of attention (although she was very busy and got tired towards the end

) I don't know if she ever did it again, but I'm sure it's an experience she will never forget.