Scarlett, I'll try to answer your questions directly:
I've been to several FKKs and other similar houses in Europe over the last couple of years. I've never run into a colleague. You have to basically go with the flow. You wear a robe or towel just like everybody else. My German is non-existent, so it's tough to carry on a conversation with any of the girls or any other of the guys in a club. Every so often, you find somebody who wants to practice their English on you, which is great.
I prefer a different kind of FKK, called a "Partytreff" (Party House in German). You pay a flat fee and can have unlimited sex with the women in the club. The women in partytreffs tend to be older -- 35+, but, since I'm almost 55, that's OK. You basically sit around and talk with each other and, when you're ready, go off and have sex.
You have to get over the fact that someone may be right next to you watching you pound away or receive a BJ. You have to get over the fact that there might be another guy right next to you with a hard-on waiting his turn. This is especially true in the partytreffs which have orgies scheduled every couple of hours. I've been to a swingers club in Amsterdam at which there were several "pros" brought in to service all the single guys. You just have to focus in on your own hard-on and disregard the sweaty guys on either side of you. Once she puts your manhood in her mouth, it's almost surreal.
The problem I've had is that I've basically been spoiled rotten by the open attitudes in Europe. For the most part, I'm just not interested in P4P in the U.S. anymore.