Thinking about: Group Sex

I've always said that I am not into sharing, but lately I have been thinking about threesomes and foursomes and more...and I realized that part of my shyness is that I have almost no experience having sex in front of other people--or with more than one person at the same time.
Wanting to experience that makes me want to find a way to try it--but it also makes me feel shy.
I would imagine that having sex with group can vary depending on whether you know them all well or whether the whole point is to have anonymous sex. For me, I think I'd be more interested in acting out with some people I knew--or could know--the anonymous stuff is stimulating, but something I can see keeping more as a fantasy than a reality.
Right now, my free time is so filled with seeing Z--and G is coming to visit in December--I don't know that I have the means to act on these impulses, but I am thinking about it....it would be interesting to meet someone who was into more of a sharing scene and experiment with them a bit...and have it be great, of course!

(Note: This concept doesn't have any significant BDSM in it--goal here would be sensuality and fun.)