I called my mum Liz one time,...and regretted it....
You know that Pop can be a shortened version of Poppa, or even, going back further, Papa? At my Catholic school the headmaster was one of a number of priests that were also university trained teachers.
Lesson number one, when attending a catholic grammar school, make absolutely sure that you are not within earshot of a priest if you replace the formal address of a priest, namely Father, with the sobriquet: 'Pop.' Calling that headmaster "Pop Cashin," instead of Father Cashin, had me in front of the owner of that name in order to explain myself.
Thankfully I was blessed with quick wits. "Father," I said as respectfully as I could muster, "today I learned why the expression: "walls have ears, is one to pay attention to." Father Cashin had a way of telling you that he was listening, it was a comical way, but nobody ever dared to even so much as smile when he did it. Father Cashin could raise a single eyebrow, and that was what I was looking at.
"When I said Pop, it wasn't mean't as any sort of rude or disrespectful insult, far from it. You are known as Pop Cashin by all the pupils in a kind of endearing way." Father Cashin dropped the eyebrow and raised the other one. I tell you, when you are in front of a headmaster that can do a cancan with his eyebrows it's difficult not to smirk, but I didn't. Instead, I read the body language.
"You are, Sir, I went on, forever Father, and I would never even think it otherwise," adding, "but boys are boys." Which somehow shifted the blame onto my cohorts. Father Cashin gave me a lesson about respect, I looked like I was appearing to pay attention, but in my heart I knew that this was a verbal warning, next time I would be facing a flogging. "Yes Father," I said, when he had finished, and with that I was dismissed.