UPDATE: There was really no need for concern over wearing undies or not. I went for the ultrasound, but the technician examined my lower stomach region, just pulling my boxers down just a little bit, not even exposing my man parts. A cyst or "dark growth" (the doctor's words) present so I will have a cat scan this Monday, October 31. I will probably go commando this time, wearing my shorts if the weather is warm enough.
I always wore underwear to work, but began going without under gym shorts at home many years ago.
Some time later, I stopped wearing underwear under gym shorts unless I was going to the gym.
Beginning about 6 years ago, I started skipping underwear at time under jeans, then dress shorts, then casual slacks.
Always wore underwear to work, even when wearing slacks I would wear without otherwise.
Once I retired, I found myself wearing underwear less and less.
Strangely enough, one of the last places I wore underwear was the gym.
After being retired about a year, I began reducing my underwear supply from about 20 pair to 10, then 6 and 3 shortly thereafter.
Eventually went to 1 and then 0.
Have't worn underwear more than a handful of times in the past year, once in the last 6 months and not at all for 3 and don't expect to ever wear it again.
Feels great to go without.