Teaching Frances Cockney rhyming slang

“I’m just going up the apples and pears,” said Lew, without explanation.
Frances looked puzzled. Lew pointed to me for the answer.
“You know, Cockney rhyming slang. He gets into it sometimes,” I said, still a bit morose.
“Oh, apples and pears, stairs – I got it.”
“She’s got it,” said Lew, chuckling to himself as he mounted the stairs.
“Where you off to then?” I asked.
“Just got to see a man about a dog.”
“A man about a dog?” asked Frances.
I pointed to the closing toilet door. Frances asked what was the rhyme in “man about a dog.” I told her, I did not have a clue. My old man and his expressions! But at least that one had caught me smiling again.