I would probably be down for DPing a chica; I my sack doesn't hang low, so less chance of bag bumping.
I don't think I'd be able to go through with DV though. I'm not homophobic or anything like that, but that doesn't mean I enjoy the idea of knowing my rod is sliding against another man's rhubarb. Chances are, it would take me out of the mental game.
As far as a GB... I think that would be interesting, to say the least. The idea of being part of one has crossed my mind before, but never to an extent of thinking it would ever be plausible outside of porn.
I do; however, often wonder if I'd be able to keep up in a reverse GB scenario. I figure I might have a shot of going the distance with 3 women, but anything more than that and I'd probably need medical attention at some point. Would be a great way to die though.