Yeah, I was at a gangbang and one of the women wanted a DP. For whatever reason, I ended up being part of it. She was riding me and another guy was in the doggy position.
Can't say it did anything much for me personally. I'd quite happily do it again, either in the same situation or if a partner wanted it, but I wouldn't go out of my way. I'm glad I did it once at least, just to have the experience.