Since I don't care much about what others think of me, I would have no problem doing it for a group of people with the same interest. I am very familiar with a nice older couple with dogs and the last time I was with them there were two other persons also present. My friends did ask me beforehand if I objected to them staying while I had sex with one of their dogs, but I didn't and it was a very pleasant evening. For a larger group I would also do it, for any commercial video recordings I would wear a mask ... I think.