I lose my boxers very easily... Perhaps somebody is stealing them at the laundromat. Either way, I run out of boxers fast, so I just do the smell check. If they don't smell bad than they are good to wear. They never make it past the smell test more than once though...

Once I run out of reusable boxers and still don't feel like doing laundry, I wear gym shorts. It all works the same if you ask me.