I've read the description of a FKK but what do the letters stand for?
The clubs really don't have anything to do with nudism, but they use the abbreviation. I'm sure actual nudists aren't too happy about it, since nudism is explicitly not about sex.
Unfortunately it looks like your attempt to purchase VIP membership has failed due to your card being declined. Good news is that we have several other payment options that you could try.
We thank you for your purchase!
Membership should be activated shortly. You'll receive notification!