A bit of how's your father (Sex)
Harry Tate (1872-1940) was a music hall performer (he is honoured in cockney rhyming slang where "in a bit of a Harry Tate" means "in a bit of a state").
One of his sketches had him on a couch trying to take advantage of his girlfriend but, whenever the young lady was about to yield to him, her father would appear and Tate would nonchalantly lean back and enquire: "Tell me, how is your father?"