There’s an old joke north of England joke, to understand it I guess you’d have to understand English working class fast food culture.
“How do you know a Yorkshire girl has had an orgasm?”
She drops her bag of chips.
(To date there are no recorded instances of anyone proving they understand Yorkshire.)
There are no hard and fast rules about duration, it depends on circumstances, if you’re having a twopenny upright in the alley behind the fish and chip shop you both want to get on with it because your chips are going cold. Likewise if you are at work and have stopped the lift between floors, because you never know when some spoilsport will call the janitor.
On the other hand if you are in a five star hotel, occupying a room with an Emperor sized bed, a Jeroboam of Champagne in a chiller on the bedside cabinet and the partner of your dreams you might want to stretch it out for a few hours.