The following innocuous-sounding phrase
There's a star in the East
is a British euphemism that warns a gentleman that his trousers have not been closed properly. The British writer Philip Howard states
There are twee euphemisms for conveying the message; I suspect that they have military origins. For example: 'There's a star in the East,' and 'Are you feeling the draught?'
Is there any truth in the affirmation in bold?
Is there an American English equivalent that I can use in polite company?
This was supposed to be the third question of "Your fly is open" "You mean my flies?" but I thought better of it, changed my mind and so here it is.