S.H.
sorry, I've recommended this before .....& it's still hard to share/write:
barrier cream for incontinence works wonders for chafing, for preventing sweating in skin folds. The original formula Desitin also works.
I have found that many people are offended by the thought of using either of these products, but they work wonders. It is amazing how much they help. I have issues with yeast infections along my c-section scar.....& the men in my house have issues with crotch rot in the summer. Both of these products work for all of us......
& I do believe the boy shorts are part of the problem. I would recommend a full brief. Switching to an all-cotton product would also be beneficial....both with the underwear & with the choice of clothing. Polyester, nylon, & spandex are all non-breathing fabrics.....& are known to accelerate sweating & chafing.