Dean Martin knew, but if you asked him he just smiled and said, “Maybe kid, maybe.”
And Sammy Davis Jr knew, but he always shrugged with his usual jive “Don’t know nothing about THAT, man.”
Of course, Frank Sinatra knew, but he would screw up his eyes and shoot you a look that made you remember your place.
No-one said anything, but it was always understood.
And that, it seemed, was enough for everyone.