4. Wear proper gym clothes and then launder them.
Even if they say “sweat wicking” or “performance fabric.” Even if you don’t think they smell bad. Unless you are a contortionist then you won’t be able to check your own crotch area and I strongly discourage you from asking someone else to check. That is not the proper use of a Gym Buddy.
Another tip to avoiding the dreaded swamp crotch or other unsightly sweat marks is to skip light colored cotton. Gray is the worst offender but I’ve seen it happen even with basic black.
Stick to lycra or spandex on the bottom if you are wearing something form fitting. If it’s loose then you have more latitude – just don’t forget the undies!