Flying alone across the Mojave Desert one afternoon years ago, enjoying the solitude, I got a 'semi' and and great idea all at the same time. I unhooked my parachute straps, zipped up my flight suit (the middle zipper gratefully goes both up and down) and brought it out for a little fondling. This always feels good just for itself alone, but when it started feeling really good, and getting harder, and I knew this one was not going away. So I levelled off at 5280', and finished the job. The rest of the flight, I had to fight to stay awake.