It’s starting between my son and daughter. At seven-and-a-half and five years old, their nicknames for one another are de-evolving from endearing to biting. So far, it’s their tone of voice more than their words that conveys their mutual disdain.

“Hello, Sirrrrrrrrrrr!”, my daughter will hiss to her brother as she climbs into the car after school. They’ve been apart all day. Sharpening their tongues.

“Don’t call me ‘Sir,’ Ma’ammmmmmm.”

I sit in the driver’s seat, pummeled by waves of amusement and dread. If Mike Judge were to write an epidode of “Alvin and the Chipmunks,” this would be it.

Policing potty words, re-setting tones of voice, correcting grammar—all of these are easier calls than reff’ing nicknames. My son knows that “PooPooHead” won’t fly, so he goes with “KooKooHead” instead. His sister’s ire explodes like a firework. The clever boy is both safe and satisfied. Do I make him apologize? Before I can decide, I peel my daughter’s fingers off his arm. His capillaries refill.

The verbal pyrotechnics are lit in large part for my benefit. I know this because on Sundays, Joe lets me sleep in. With him, the children frolic in fields of sibling bliss. No arguments, insults, or slap-fights reverberate up the stairwell. I doze on and off, wondering if anyone’s even home. When I come downstairs, Joe’s actually reading, and the children are spooning under a tent they’ve fashioned from bed sheets.  Then, in the time it takes me to pour a glass of  juice and find a ponytail holder, they’ll ditch the tent and start swinging their Razors around at each other like noisemakers.

Where do I draw the line on name-calling? I tell the kids that families are a refuge, that we have to take care of one another. On the other hand, I realize that verbal sparring is how Nature thickens our skin. When I was growing up, put-downs and name-calling were Olympic events for my siblings and me. At first the insults were the usual potty-centric variety. Later, in our middle and high school years, they became more sophisticated–or so we thought. My younger brother and I especially duked it out. “Deine mutte!” he’d yell if I asked him to turn his Zepplin down. I would return with “Ma mère est ta mère, tête bête,” and slam the door.  When my tenth grade English teacher assigned the book “Word Power Made Easy,” I found a treasure trove of adolescent-appropariate ammo. “Yeah, get your nadir out of here, sebaceous face!” I’d call as he pedaled off on his Mongoose. He’d loop back towards our driveway to volley back a “Whatever, Braille forehead!”  These exchanges helped make me a nimble debater in the halls of my college dorm. Whatever I lacked in facts, I made up for in snappy comebacks and clever tangents. These skills served me during architecture school critiques, too. They still come in handy for the occasional off-color comment on the job site.

For now, I’m letting my kids have at it, as long as the language stays clean and no one gets too rattled. Sometimes one of them will craft a name so witty, I’ll become more fan than referee. “Burn!!” I’ll think, just like I used to yell.