She will not throw a tantrum when she's upset. Tears won't brim perilously over the eyelid ledges scalding the rims. Instead, all she will do is purse her lips in vigorous disenchantment, in what is commonly called a pout. And that is the only sign she will offer.

Had Matthew, aged nine, been driven to similar lengths he would have demonstrated his feelings most audibly. Matthew is given to chucking all handy objects at the walls as though he's practising a course in accurate projectile hurling. There's an impressive line-up of mauled and mangled joysticks, remote controls, battery chargers and PlayStation game covers all over the room — like witnesses waiting to testify in an assault and battery case.

Matthew's sister, Jilly, just eight years, displays her frustration differently. She possesses a primeval scream that is unleashed on the unsuspecting household — a thin, prolonged high note that makes the hair on the nape and arms stand to attention. This scream, after knifing upwards through the air, generally spirals down in a disconsolate wailing that can continue endlessly.

But Mary Anne, glasses perched perilously on the end of her nose, will merely pout. No more, no less.

And on this day, the three of them — Matthew, Jilly and Mary Anne — are all gathered at the video game store where PlayStation games are being sold at throwaway discount prices. It's a rare clearance sale and Matthew and Jilly are agog. Their excited feet carry them, dancingly, first left then right then left again as they try to take in every game on display on the long rows of shelves.

"Look, look Jilly, here's what you were wanting last Christmas." Matthew names a game and Jilly hurries over to look for herself. In her hand she clutches a dainty embroidered bag, its mouth held together by two gold-plated clasps. The bag contains her savings (pocket money, plus a secret bonus from dad to invest in a video game or two).

Matthew carries his spending money (including a secret donation from mum, not dad) in his brown ‘big boy's' leather wallet. He is almost breathlessly taking in the range of what is available so cheap. His nine-year-old mind is making feverish calculations.

Jilly, meanwhile, buoyant with her own excitement, has run over to Mary Anne, tugging her hand, pulling her along, saying, "Look, Mary Anne, look at all the games. This one we've played together. Remember? And this. And this. And this. I think you got better scores than me every time".

Mary Anne offers no comment. Her pout is in place and all she wants to do, one imagines, is to get out of the store quickly. But Jilly, blinded by this incredibly joyous moment, is not aware of any of Mary Anne's pouting.

"Which game are you going to buy?" Jilly asks and Mary Anne's hand goes rigid in Jilly's. "Which one, Mary Anne?" repeats Jilly. Mary Anne, thawing momentarily, loosens her lips to exclaim, "I can't. I've been banned from playing".

"Who by? Mum?" asks Matthew, overhearing and coming up to join them.

Mary Anne can only nod. In her disappointment, she cannot trust herself with speech. "Why?" asks Jilly, frowning and giving it some thought, "Is it because of your eyes?" Silence.

"Is it your eyes?" Jilly persists.

Again, a nod, albeit so slight it nearly goes unnoticed.

Mary Anne is distraught. She loves these games. She is always ‘transported'. She has played six hours straight, for days. She is skilled. She is good. She is, in fact, very good. She is, admittedly, addicted. She is 74. And she is pouting.

Kevin Martin is a journalist based in Sydney, Australia.