Do NOT let your skinny jeans come between you and a quick lay.
At my first party, I wore a snug pair of jeans, coupled with a boobtastic top that managed to make my 34Bs look more like 36Ds. My hubby couldn't keep his hands off me, and we eventually retreated to a dark corner for heavy petting and an attempt at full-on fornication. Lord, did I regret wearing those jeans. I didn't have any problems locating his most erogenous of zones, my clit was a bit more elusive. While crotchless panties aren't exactly my style but a sexy skirt would have given his ding-dong a greater chance of reaching my jelly roll. Next time you're suiting up for your local group grope, seriously consider the minidress. Sans panties.
Do NOT ride the sex swing with a complete stranger without your partner's permission.
Even in the most open of relationships, boundaries should be set to account for varying comfort levels. Play parties can be especially fraught with tension, since you're basically philandering in front of each other. Such a situation can be an incredible turn-on for some couples, but jealousy is still possible so you'll probably want to regulate the level of physical contact allowed with others. Or perhaps you'd like to create a rule stating that new boy toys must be shared. Whatever it is, make sure the parameters are clear before attending a gathering of libido-crazed men and women. In addition, I think it's only logical to point out that preordained rules should not, under any circumstances, be broken. Even if that guy over there has a cute butt, or that chick can do amazing things with her tongue, such rule-flouting spontaneity could serve to undermine the very foundations of your relationship. If, after observing some interesting sexual possibilities, you feel that you'd like to raise the stakes next time, bring up the issue with your partner. There will always be other orgies, and there's no rule saying that your MO can't evolve.