It was the "naturist" thread that got me thinking about this, and I don't mean "daring" as in bungee jumping/white water rafting/swimming with sharks kind of way!!
When exdh and I were "walking out", there was a day that I knew his parents were going to be out. I thought I would surprise him, so I went to his house on the bus, got off at the appropriate stop and walked the couple of hundred yards or so to his house.
He let me in and offered to take my coat. That was when he discovered that all I was wearing underneath was a set of black lingerie, complete with stockings and suspenders.
I had taken clothes with me in a bag for the journey home, but heaven knows what would have happened if the bus had crashed!