Where is the ideal place to have a private conversation? Why, over your mobile ’phone from a train, of course, & do stand at the joint between carriages, so you’ll have both sitters & standers to hand.
Then ring a friend who’se just had a baby, only to discover (loudly) that a pair of mutual friends have separated.
At this point, it seems necessary to say something like “between you & me...” then continue the discussion even more stridently.
Maybe 30 people were fascinated to learn the recent amorous history of two people who weren’t even named. Loudly.