Not to be dramatic, but there is an empty space on the sofa when I sit down each night.

It’s a glaring chasm, a vast abyss, an aching void – of where my son’s cute little butt once was.

Winston, now 13, has officially hit a milestone not written about in parenting books, but wildly significant just the same.

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It’s the milestone of a child no longer wanting to hang out with you.

It’s just been me and Winston for almost 11 years, and our bond is generally remarked on by anyone who knows us to be exceptional. Our relationship is the greatest joy of my life, and yes, I would count my wise, kind, super funny kid as one of my best friends.

I haven’t depended on my child as a friend as such, but he’s the only person I’ve shared a home with for more than a decade, so to me, it’s inevitable that we’d be close.

No, I haven’t depended on him; I have my own friends and interests. But I have enjoyed my son’s company immensely, and now that’s being withdrawn – by him taking to his room after dinner every night - it’s creating an ache in my heart.

But we all know this is coming, right? As mums, we should be prepared for the inevitable separation as our kids forge their own identities, become independent, which is exactly what we raised them to do.

Sure. That’s all bloody well and good,but it doesn’t mean we have to like it.

For me, Winston’s decision to spend more time in his room than with me did not come gradually, but suddenly, unexpectedly, like a massive slap in the face for which I was totally unprepared. (Yes, that’s a little dramatic for effect.)

For context, this is what our movie nights looked like for our entire history:

Then, four weeks ago, when I suggested a movie, Winston said, “no thanks, dawg” and bolted to his room – taking with him the only a box of Tee Vee snacks, to add insult to injury.

What I didn’t add in my Instagram post of this significant night was that later, I busted him watching that very movie I had suggested in his room without me.

Oh, my heart. It wasn’t that he didn’t like my entertainment selection; he just didn’t want the experience with me.

Winston, finally at 13, is rejecting my company.

Now, this is our new norm. There’s no hanging out after dinner on the sofa. No huggles while we scream at stupid decisions onThe Bachelorette. No dipping our hands into the popcorn bowl at the same time and yelling “It’s my turn”.

What we have instead is laughter from the other room as Winston games online with his mates, or FaceTimes his crew.

As one would expect, I have taken this new stage gracefully – on the surface. How lucky am I that my son is developing his identity and independence in this way? I certainly don’t take that for granted; I know it’s something not every parent gets to experience.

And so, as he blows me an air kiss and breezes off to his room, I fleetingly think about how this is the circle of life … and then call my mum to whinge about it.