Loads of times.
On holidays with friends staying in a rented house/villa, I have often been naked all day around the house and pool, and the only one who is.
On beaches - non nude beaches, I've been the only one naked many times.
Just a few weeks ago in Spain I hiked naked and joined up with a group of 50 clothed hikers and walked/chatted with them for over an hour.
I've still no tbeen oon at a party though.
