His voice sounds as though it has recently broken, a little raspy, mostly deep, occasionally betraying him with a slip into squeakiness.
About13, maybe just 14, and blond, like his mum, who's about 30cm shorter. They're standing outside a shop, with a fair-haired sister a few feet away, texting, oblivious.
The half-boy half-man is sobbing, heaving great breaths in and shuddering them out. "I'm never going back, never, I'm not, not there, not to that stuffed-up place." His face is red and wet under his baseball cap, his mouth stretched and turned down at the corners, that crying-grimace that shows all your teeth. His mum is trying to hug him, which he's allowing, probably only because his mates aren't around.
Who knows what happened to cause this Saturday-morning scene in suburban Auckland - maybe a shopkeeper accused him of pinching things, maybe some cool girls teased him in the surf-shop, maybe he was shouted at for spilling his drink in the cafe.
Whatever, it must have been the sort of everyday humiliation which makes adolescence a miserable tunnel of pain, a great big reminder that he's alone, nobody understands him, the world is stupid, everything's unfair, everyone sucks.
He can't stop himself weeping, which is making it all worse; now everyone probably thinks he's a baby, everyone's staring, everyone's laughing. "I'm not going back, I'm not, they're just ****ed, mum."
The swear-word dissolves Mum's sympathy in a second and her words of comfort - "It's all right, darling, it was awful, you're right, we don't have to go back" - turn into admonition: "Robert! Don't you speak like that! We do not swear!"
Poor little bastard. Not even his mum's on his team now.
She's still patting Robert's arm, still trying to hug him, but she can't let an obscenity go, must set boundaries. That's what you have to do with teenagers, isn't it? Otherwise, before you know it, they're smoking crack and robbing dairies.
The little drama between Robert and his mum - which lasts all of 10 seconds - is a tiny flash of recollection, a reminder of how awfully lonely it is to be a teenager. There you are, trapped in this limbo between Xbox and pushbikes and dolls and pimples and sex and drink-driving, and not even your mum gets you any more.
But maybe mum's just terrified.
As a society, we seem to be perennially petrified of teenagers, of their fragility, their potential for sudden emotional eruptions, their sensitivity to any hint of mockery, their potential for violence.
The British papers are full of the new incarnation of adolescent horror; a kind of gang-bashing known as "happy slapping", where a bunch of kids approaches a stranger, often a homeless man, pushes him to the ground and kicks his head and body until he stops moving.
A gang of four youths was sentenced at the Old Bailey six days ago to manslaughter sentences of between eight and 12 years for the "happy slap" killing of young Londoner David Morley, whom they accosted one autumn night in 2004.
One of the killers, Chelsea O'Mahoney, was only 14 on that night, when her gang (the others were aged 19, 16 and 15) attacked eight strangers including Morley, who died of a ruptured spleen after more than 40 kicks and blows.
Closed-circuit television footage of one of their attacks shows the gang's boots crunching into the head of a homeless man huddled against a wall, as O'Mahoney stands back, calmly recording it all on her video-enabled mobile phone.
The "happy slapping" phenomenon, which reportedly began as a schoolyard game of accosting another kid, slapping his or her face and using a cellphone to record the astonished reaction, has plainly turned ugly, and each week there's a new incident being reported.
It's interesting to see how this is being interpreted by many British commentators as evidence of some new kind of teenage menace. Many of the press reports give the impression that these teenagers have been warped into little savages by their cellphone cameras, or by television programmes such as MTV's Jackass and Dirty Sanchez, which feature the kind of dodgy stunts and violent practical jokes (like do-it-yourself genital piercing and drinking one's own sweat) which teenage boys find hilarious.
It's all so familiar, all reported with the kind of lost-innocence dismay that accompanied stories about moshing in the 1990s and skateboarding gangs in the 1980s and rock'n'roll in the 1950s, the sense that an entire generation is suddenly different, suddenly wild, suddenly prey to all sorts of sinister influences that never led their parents astray.
It's far too simple to be plausible, isn't it? Gang violence has existed forever, and there have always been rotten little beasts kicking people's heads in and beating up grannies. Moral panic about the youth of today is just as unrealistic now as it always was, and that's why it was oddly reassuring to see Robert grappling with life and his mum, just as his parents' and grandparents' generations did.
Despite the disturbing stories, it's nice to know adolescence has not suddenly become Chelsea O'Mahoney and her mobile phone; it's still Robert, sobbing on the footpath, sensitive and misunderstood and unappreciated and perpetually embarrassed. What a relief.