The child you raised will all but disappear — and not just into the confines of their bedroom.
Their personality will change, actual speech may cease altogether. It could, however, be replaced by intermittent grunts and frequent text messages ... if you're lucky.
Your opinion will count for nothing.
The teen will instead find their validation courtesy of the highly anti-social social media. Desperately seeking the approval and praise of "friends", most of whom they have never met and, in all likelihood, never will even though they're literally prepared to share pics of their privates publicly with virtual strangers ... just to be "liked".
Your beloved child will go from tossing a ball to not giving a toss about anything or anyone but themselves.
On the occasions that you dare to venture into their dank and darkened room to gather laundry or retrieve the ginormous mound of discarded pot noodle containers, under no circumstances should you turn on the lights or pull back the curtains.
This may result in blindness — aversion to light is a common side-effect of hours spent away from the real world.
You may even be fooled into thinking their room is vacant. Look up. You will undoubtedly spot them suspended upside down from the ceiling in their new batlike form ... grabbing 40 winks.
Seize this moment and call pest control immediately to have them tranquilised and rehomed. Problem solved!
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The change will be more subtle and will invariably start with the creation of a profile on an online dating website.
Months — and, in severe cases, years — later they will emerge from their bedrooms, brokenhearted, sporting chin hairs so long, they could be braided. Many may need rescuing by emergency services, forced to clamber over the dangerously discarded mound of cheap, empty wine bottles.
Their bank accounts will be as empty as the promises of the Nigerian catfish who just scammed them.
No, apparently the broken English and frequent requests for cash raised no red flags. Nor did the Darth Vader-like voice-changing machine employed in rare phone calls, or the fact that despite being available the world over, Skyping was never an option.
Yet, as she attacks her now overgrown leg hair with a weedeater, her humiliation will also bring closure ... knowing that the public sharing of her private shame could prevent it happening to someone else.
For those not so willing to forgive, hellbent on revenge and with nothing left to lose except some weight, they will subscribe to a Wine of the Month website, become an online stalker to perceived scammers and ultimately end up appearing on our screens in an episode of Women Behind Bars.
Do I even need to go there? They'll simultaneously discover porn and the Canadian Pharmacy.
The courier who delivers their "special blue pills" will see them more often than their family and friends. The drool encrusted singlet, worn for weeks, may need to be peeled from their body and should be incinerated upon removal.
Please, to preserve your own sanity, do not bring an ultraviolet light source to these premises. There's no guarantee that ACC will cover any PTSD counselling.
On the upside, the recycling centre can expect a massive dump of pizza boxes and Tui cans.
Sadly, the truth is what makes stereotypes stereotypical.
Foetuses will be implanted with digital devices as soon as fingers are formed so they can text you their dietary requirements, advise of food allergies and their preferred pronoun, tweet of impending contractions and announce on Facebook their ETA.
They will enter this sorry world complete with Instagram accounts and YouTube channels.
Still, I don't recommend the introduction of a selfie stick, in the womb.
Babies born in the United States, however, may emerge packing a Magnum or AK47, their firearms licence having been approved in utero.
That's technology for you. It's our best friend ... or so they would have us believe.
*Kate Stewart is a successful scone maker and pot stirrer. Her, as yet, unrealised dream of five-ply, coloured toilet paper weighs heavy, unlike her columns — feedback welcome: firstname.lastname@example.org