Important cycling clothing question..

Something that I’ve been pondering for a while now is the question ...

Why don’t cycling shorts have a fly? I have several pair of liner shorts designed to be worn with pants or shorts in lieu of regular underwear and none of them regardless of brand have a fly..

I’ve been giving this a good deal of thought and can’t come to a good rationale why a manufacturer wouldn’t include one for men’s liner shorts ...

clearly this is a problem in need of a solution