Britney Spears' Plush Birthday Onesie Shows Us She Is A Kid At Heart — PHOTO

Underneath all of those crop tops, cut-off jeans shorts, red latex, and that sex kitten, breathy vocal style, she's still a kid at heart. Britney Spears wore a plush animal onesie while celebrating her 34th birthday on Dec. 2. It was insanely adorbs, like Brit Brit herself can be! The cozy, gray "outfit" came complete with ears and a face. I can't quite tell if it was some sort of bear or not, or if it was an actual onesie versus an actual robe. But that's pretty much immaterial at this point. All I know is that it was crazy cute.

The singer posed with her teacup birthday cake and an ear-to-ear grin, with her hood atop her head.

This image really struck me for a very key reason, besides the fact that the singer was being all sorts of playful.

For so many years, Spears' image oozed sex appeal. It's always fun to see her strip away all those glossy, pop diva layers to show us her sweet side. It's easy to forget that the Holy Spearit started out as a southern girl who eventually grew up to be a mom of two super rad sons. Those are the bookends of her life, with her crop top, teenage dream '00s being internal chapters in the overall Spears story.

Spears is almost too cute for words in this bday pic. No, she is too cute for words.

Her pal Miley Cyrus is also a huge fan of the plush PJs/robe/onesie. She just posed in a pink sleep outfit while snuggling with one of her pooches. Can I get an "Awwww!?"

While Ariana Grande wore a onesie with heels at the airport, Spears' onesie isn't really an outfit that you go out and about in... even for Starbucks runs, during which Spears is always hounded by paparazzi. It's more for a fun for, say, a slumber party.

That's the ticket! If you want to have one of those with your pals, well, here is an option for your plush PJs.

This super cute koala outfit is a totally new take on sleepwear. I seriously want to invite all my BFFs over for a sleepover. The only requirement will be that ever attendee who is crashing out must wear a plush onesie, robe, or PJs. Like Britney Spears! ($33.50, aliexpress.com)

Oh, and ICYMI, check out Spears' glittery, self-referencing booties.

Images: Britney Spears/Instagram (1); Miley Cyrus/Instagram (1); Courtesy Ali Express (1)