TO ONESIE or not to onesie? That is the question.

You must know what this means. The “it” garment of 2012. The must-have item for girls, boys, men and women across the land this Christmas.

And if you’re not familiar with the concept, here’s a definition: “An infant’s one-piece close-fitting lightweight garment, usually having sleeves’ but leaving the legs uncovered and fastening with snaps at the crotch”.

Also known as a babygrow and — unless you’ve been walking around with your eyes shut for the past six months — you’ll have noticed that everyone is wearing them.

Rihanna, the One Direction boys, Una from the Saturdays, Joey Essex — a whole host of A-listers through to the Z-listers have been spotted wearing these snug numbers.

Now I’ll be the first one to admit that I love to follow a fashion trend, but everything about a onesie initially screamed “no” at me.

I already look about 12 years old (I’m 25) without wearing a giant babygrow, but I was willing to try a few on in the name of research and see what all the fuss is about.

First stop was Beales in Bolton town centre, which kindly let me sample a few for size.

Now the first thing I’ve noticed about onesies is that they’re all in garish colours and animal skin prints.

But then again, let’s be honest, it’s too late to be a wallflower when slipping on a giant babygrow.

I go for a bright pink spotty number, and as I do the buttons up and catch sight of myself in the mirror I feel instantly ridiculous as I look at the children’s book character staring back at me.

But hang on a minute — this feels nice. Really nice. I feel all warm and have the urge to curl up in front of the Strictly Come Dancing final with a mug of hot chocolate.

Maybe they’re not so bad after all.

And that seems to be the appeal for children, teenagers and adults across the board, as Alison Cash, fashion manager at Beales explains.

“We have sold them to grandmas buying them for their grandchildren, through to teenagers buying them for themselves,” she said.

“We’ve completely sold out of the leopard print ones.

“I think it’s because it’s a fun thing at the moment and all of the celebrities are wearing them.

“I’ve also heard that a lot of people are wearing them as a family on Christmas day — a onesie day.”

Now there’s a thought — my nana, grandpa, mum, step-dad, older sister (she’s a solicitor) and I all watching the Downton Christmas special in our onesies. I’m still not convinced.

Next stop it’s New Look in Bolton, which clearly has the best range in town for teenagers and women.

I’m overwhelmed by all the patterns — but then I spot the one for me.

It’s red and spotty with a Santa hood trimmed with white fur. I must have it!

I try it on and feel completely chic as well as convinced that onesies can be stylish.

I corner one shopper, Madeline Brown, from Harwood, eyeing up the onesies to get her take on the craze.

“I’m getting one for my daughter for Christmas,” said the 64-year-old. “She’s 24 and she likes to come home and lounge about in her comfortable clothes. I think it’s just another trend which has caught on. They’ve got some really jazzy ones here.”

Finally I pay a visit to Marks and Spencer, the king of quality sleepwear, to see if they have cottoned on to the trend.

And lo and behold, in the store’s front window is a mannequin in a red-number — the very one fronting their Christmas advert. Unsurprisingly, it has almost sold out.

Now the “all-in-one sleep suits”, as they’re called at M&S, are certainly more conservative, so I go for a more subdued Me to You Bear beige onesie with white spots.

Soft and not so silly, this is definitely a more mature onesie, if such a thing is possible.

They are also excellent value for the quality, now on sale for £18.

So with my day of onesie-shopping coming to an end, what’s my verdict?

Well, there’s no doubt about it. Onesies make you look ridiculous, especially in animal print or with any sort of ears or tails. Plus, they’re unflattering and make you look like you have an elephant’s bottom.

But that is all part of the fun. Like Christmas jumpers, there is nothing wrong with poking a bit of fun at yourself, no matter what your age.

And they are so comfortable and warm, they make the perfect winter hibernation outfit.

But for goodness’ sake, boys and girls, mums and dads — do not leave the house in a onesie. It’s the ultimate crime against fashion this Christmas.