"PLEASE," implores our eldest, "can everyone just pretend to be normal for one night?" His girlfriend is coming to dinner for the first time and he could be forgiven for being a little apprehensive, given this family's history of tableside behaviour.
"I'm not sure I know what you mean," I mutter defensively, getting up from where I've just been crawling around the kitchen in my dressing gown talking to the dog in what I think is a pretty good impersonation of Bart's bespectacled buddy Milhouse from The Simpsons.
To be fair, I may have some idea. Dinnertime in our house, despite all good intentions, is routinely a test of patience and sanity for everyone concerned.
It begins with the ear-shattering clanging of a cast-iron dinner bell on our kitchen wall, something we picked up at a market once -- no doubt originally designed to call workers from across fields for feeding, in its current confines it's more apt to set off car alarms outside.
Three of our four then file in to set six places around the long table, so that -- once the many candles we always have are lit -- it all looks a bit like the opening scene of some surreal dinner-party in a Luis Bunuel film, but with the cast of the Addams Family.
Our youngest, the girl, will then tug a single pathetic morsel disinterestedly around her plate before dissecting it with the slow and deliberate suspicion of someone trying to pry open a coin purse with a pair of knitting needles for fear of a spider inside.
Her older brother, who delights in horrifying us with his eating habits, will have the most space around him and the undivided attention of the dog as he finds some depraved new way to force as much into his cheeks as possible. And the second eldest, who now converses entirely in deep sighs, disgusted clicks of the tongue and the occasional monosyllable, will sit hunched over his helping, silently hidden in hair as his mother attempts an interrogation.
Last to arrive is the eldest, who requires several private calls before deigning to tear himself away from higher pursuits to join the proceedings which he will observe wearily from as far away at the table as possible with barely concealed disdain.
His dad, God help him, is possibly the worst of the lot. I tend to get terribly over-excited when it comes time to eat and will, at the very least, rock merrily in my seat, giggling and chirping between mouthfuls, Rainman on laughing gas. I've even been known to disappear beneath the table shrieking as if attacked by a shark, simply because I happen to think this is hilarious. Perhaps it's a blood-sugar thing.
So while we'll occasionally manage to muddle through mealtimes with a half-hearted stab at something resembling normality, at best it's like being at one big Mad Hatter's tea party; at worst, the circus-sideshow feast in cult movie Freaks -- where a primordial dwarf staggers across the tabletop towards a horrified guest while the assembled carnival acts chant, "One of us, one of us..."
...Or, in short, the sort of spectacle which could quite reasonably be considered dispiriting for an 18-year-old seeking to impress his girlfriend at a family dinner for the first time.
"Sorry?" I say, shaking myself out of this disturbing reverie. "Vegetarian," repeats our eldest. "She doesn't eat meat." "Absolutely no problem," I tell him. "And hey -- best behaviour. Promise."
He looks slightly past me, creases his lips and raises one eyebrow: a resigned, deadpan expression which, were we starring in our own wry parody of fly-on-the-wall documentaries about family life, would be directed straight to camera.
What does one cook for a vegetarian teenager, that everyone might enjoy -- particularly a family which often seems to be eating six separate meals simultaneously? As it happens, we settle on Mexican -- meaning that while I stagger around from cupboard to cupboard wringing my hands in crisis, our eldest son calmly suggests fajitas, with peppers, side dishes and sauces.
Fajitas are the great equalisers, as suitable for careful assembly by our food-suspicious youngest as for flinging into the vortex that is the gaping maw of our competitive eater, her brother, or to hide under the curtain of hair perched next to him.
When our guest arrives, candles are lit but we forego the usual ritual of the skull-fracturing bell. Our youngest giggles into her fists, rapt by the presence of another girl and we gorge without fanfare or incident in a manner some might consider 'normal', for fajitas at least.
And when we finish mopping the sauces from our faces and torsos, I fetch a photo album filled with pictures of our eldest when he was small -- after all, our instructions were merely to pretend to be normal. He never said anything about not embarrassing him.
He tolerates what turns into a sound roasting, from behind occasionally clenched fingers, with admirable patience, eventually prying his girlfriend away to walk her home before the nightly ritual of washing up descends into the usual hysterical chaos of noisy recriminations.
Slipping into the quiet of the next room, my wife and I continue to pore over the album. "Look," I say, gesturing to the serious youngster with his furrowed little brow. "He was always the only grown-up, even when he was five." "I know," she says, slipping an arm through mine as the sound of something shattering in the next room is followed by a howl. "Where did we go so right?"