Going commando (Bob's fault)
You may blame Bob entirely for my asking this one.
Even in the UK we've realised that going commando means going out wearing no underwear, but why? I seriously doubt that I am meant to believe that elite US military forces have entirely rejected skivvies for some arcane tactical reason - so, the reason for this phrase is... ?
Could be they watched too many Carry On films and took up the idea from the kilted 'devils in skirts'? Actually, I hadn't heard 'going commando' before. Maybe I live too sheltered a life, or maybe it's just too damned bracing here in the frozen North.