Don’t think….. do…. Record, post and then ask. Here’s some you can get in Amazon: 
Discussion
I’m 53. My balls would still be touching fabric.
You want those traditional Indian trousers colloquially known as “crap catchers”. I never understood the practicality until travelling in India and saw a guy squat in the middle of the street midday in middle of a city and take a dump. Public but private at the same time. Very ummm professional!