Also just wear compression shorts under loose shorts
I do - but I still feel the need to do a swing test before I got out.
For no other reason than I think it's impolite to sway in a crowd. Who knows if the last wash was the final straw elasticity-wise?
Plus sometimes new undergarments don't fulfill the promise of dong-restraint that the photo on the box made.
Also - I run through a mostly Muslim community (no stray dogs) and whilst I can't hide the fact that I'm obviously a raving infidel - the locals still smile and wave - and I think a bouncing phallus might break that chemistry.