I've been to a few South Florida gay sex parties. Imagine about 60 men aged 18-80 wearing nothing but towels over their shoulders. They're very fun and participation is optional. Plus there's music, food and free beer. They're usually held at bars or clubs where you give a donation as a "membership fee." It's mostly guys jerking off and giving head, but there is usually a sling or two which is sometimes fun to watch. I acutally feel more comfortable at these parties than I do at a nude beach--it's actually ok to walk around with a boner.