I'm not sure when it began but my son's report of his day in school has taken on a whole new slant.
When he started Primary 1 in January, he filled me in daily on what he ate during recess, so thrilled was he with the novelty of being able to buy his own food.
As friendships began to cement and I grew familiar with the cast of characters that made up his class in a boys' school, I got to hear about random things that A did, B said or C saw.
But increasingly, I'm also getting daily accounts spiked with a heavy dose of schoolboy or toilet humour.
"Mama, do you know how to spell iCup?" he asked one day.
"What's that?" I asked, perplexed. "Is it something to do with the iPad?"
Dying to deliver the punch line, he cackled madly as he hastened to get the answer out: "I-C-U-P. I see you pee. Get it?"
The jokes are invariably inane and often involve bodily emissions, which are an endless source of entertainment to him and his friends.
Another day, he couldn't wait to belt out the "toilet song" a friend had made up as we drove home from school. But he was laughing so hard I caught only a few choice words, such as bowl and smell.
His favourite so far is a party trick another friend showed him, where he puts his right hand under his left armpit, then flaps his left arm repeatedly to create a rude sound akin to passing gas. "You said practice makes perfect. I'm going to practise this every day until the sound is as loud as thunder," he announced proudly.
I rolled my eyes and exchanged looks with my husband, expecting him to tick off our son for wildly misapplying the well- meaning advice. Instead, I saw his eyes light up. "Hey, I know this too," he said and proceeded to model the way it should be done, producing the desired sound at a decibel that delighted my son.
"It's a boy thing," my spouse confessed.
Another "boy thing" that tickles my son to no end is coming up with messages that he keeps threatening to stick on the back of his four-year-old sister. "Mei mei, you better behave. If not, I'm going to write 'Kick me' and paste it on your shirt," he warned amid a fit of giggles. "Or 'Call me stupid'. Or 'Dump your rubbish here'."
If only you could channel this creativity and passion to more constructive things, I tell him repeatedly.
I'm no stranger to the juvenile antics of schoolboys, having attended a co-ed primary school. Boys' idea of fun often seems to involve horseplay, physical aggression and coarse language. All the bad words I know were gleaned from the boys in my neighbourhood school.
A friend whose two sons attend the same mission school as my boy recounted how one of them, who's also in P1, went home recently and told her matter of factly: "It's wrong to say f***."
She managed to suppress her shock long enough to say, equally neutrally: "Yes, it is wrong. So I don't want to hear you say this word again."
You might think that would have made a perfect teaching moment, to expound on why the word and its ilk must forever be banished from one's vocabulary.
But dealing with schoolboy humour can be tricky. You don't want to seem like a stick-in-the-mud or discourage your child from sharing his day with you by always tut-tutting at the jokes which, while distasteful, are harmless. Yet you don't want to encourage language or behaviour that is frowned upon in polite company.
Sometimes, you fail to react in the way childhood educators might advocate simply because you are caught off-guard, like my friend was.
I, too, was stumped the day my son asked what "those two round things down there" were for. It turned out he had gone to the toilet with two friends in school and, for some reason, they had become intrigued by their private parts.
With my mind teeming with questions about why they were comparing genitals and what else goes on in boys' loos, I could not summon an enlightening and age- appropriate answer in time. "They are your private parts. This means you should not be showing them to other people or letting anyone touch them, understand?"
It was a line he had heard umpteen times and his eyes glazed over. Then, seeing that no other answer was forthcoming, he ventured his own explanation: "Oh, I know. They are what make you smelly down there. They are called stink bombs."
As I choked back laughter, I made a mental note to delegate the job of explaining the male anatomy to my husband.
My son would never know the alarm he caused me the day he said: "Mama, Seth gave me a dirty eraser."
My mind went into a tizzy. "What? So fast? They are already au fait with off- colour jokes and sexual innuendos? Should I play it cool or..."
I found myself holding my breath as he proceeded to fish out the eraser from his pencil case, which I half-expected to be of some phallic shape or with an image of a woman showing more flesh than dress.
It was neither of these things. It was simply grey and grubby from use - a dirty eraser. Mama was the one with a dirty mind.
I'd been given a reprieve. But I know these precious innocent days are numbered, especially since the all- consuming curiosity about sex is also more a "boy thing". I can only hope I won't be caught off-guard again.
How do you deal with the off-colour jokes your children crack? E-mail firstname.lastname@example.org
This article wa sfirst published in The Straits Times on May 4, 2014