Christmas number onesie

Now that the Duchess of Cambridge is pregnant, the next nine months will be filled with baby talk.

With Kate already a fashion icon, the future mini-royal will surely follow (romper) suit. The good news is, there’s no need to wait — the time for babygro-chic is now.

In the lead-up to Christmas, every shop on the high street is selling onesies — the jersey, all-in-one pyjama suits that look as though they are made for duvet days but have somehow crept out into the streets and the bars of London.

Topman is stocking them, and River Island has some with a snowflake pattern — for boys. Onesies are on the shelves of lingerie store Oysho, and the girls in the latest M&S Christmas advert are wearing them.

Here is my confession: my boyfriend and I have matching purple onesies.

Some of you will no doubt think I have just committed fashion suicide with that admission. I beg to differ. In fact, by regularly kicking back in my adult romper suit, enjoying my big nights in by wearing full-on slouch gear, I have aligned myself with the long list of celebrities who have embraced the onesie.

I am not so different from, say, pop star Rita Ora and model Cara Delevingne, who last month tweeted pictures of themselves in Kigu animal-suits. Japanese kigurumi (“costumed animal characters”) have become hugely popular with students over here. On Ora’s birthday in November, she wore an owl suit and Delevingne a tiger version.

And they are not the only one(sies). Bridesmaids actor Chris O’Dowd and his wife Dawn Porter, diver Tom Daley, comedian Russell Kane and singer Christina Milian have all sent pictures of themselves wearing jersey jumpsuits to Twitter, and last night Lena Dunham, writer and star of TV series Girls, was out in one in New York.

On Saturday night’s X Factor, Louis Walsh was shown during rehearsals wearing a green head-to-toe by Norwegian band OnePiece. He was demonstrating his support for his group Union J, who have shown their onesie love by wearing their own OnePiece jumpsuits as well as monkey-gros from the All-in-one Company.

The boys are no doubt hoping to emulate their forebears, One Direction, who are such fans of the OnePiece that they are about to bring out their own design for Christmas. In a video leaked last week, Harry Styles is being chased around by the brand’s UK rep, actress Lisa Dwan — both of them wearing a OnePiece. The One Direction OnePiece has a hand print emblazoned on the back.

“It’s at customs right now,” says Dwan. “Their fans all buy the OnePiece to be like them so they thought: why not design their own?”

Of course, I was ahead of the curve — the first to break the story in the Evening Standard of the OnePiece hitting the UK back in 2010. I’ve been lounging in my trendsetter glory ever since.