Well I believe there is a point worth bringing up about understanding the difference between fantasy and what your asshole can really handle. Even if tops are totally considerate and/or not that hung, realistically, after two or three dicks, the skin on your hole tends to get a bit raw and uncomfortable, eventually painful. Especially if using condoms. Not saying you shouldn't try it, just don't get too attached to your gangbang fantasy. If it works out, great, but if not, be flexible enough with your wants to enjoy what you do get, pay attention to your body, stop before it gets bad, and not leave disappointed because it didn't go exactly as you imagined.