Given the origin of the phrase was extremely classist in Britain. Probably peasants and surfs would be the opposite. Any form of commoner would not be a lady or a gentleman. So reminding people of that.

Though I’m sure the British would do it and I thoroughly British way, introducing Mr Bob and his wife Julia, and now introducing the gentleman lord von butterscotch and his lady affelia.

In the context you would know they were commoners cuz they didn’t get the title lady or gentleman