ggbo951a
Any tighter underpants might help, like a pair of snug 'boxer-briefs' , preferably with no seams in the saddle area, will keep your old chap and berries stationary. The constant jostling as your sack gets tossed back and forth by your legs could be what is irritating your testes.

Did you know the 'jock strap' was originally designed to improve crotchular comfort for male cyclists?