What is the opening at the front of briefs (and boxer breifs) for? Okay, I know what it's for, but does anyone actually use it? It seems far more trouble to manipulate than pulling the front of your pants down four inches. If no one uses it, why is it still there? It seems to add extra fabric and stitching that cost-reductionism would have eliminated long ago. Is it simple industry momentum? Does it add something to the comfort I don't see?