Kim Kardashian awkwardly showed up to 50th birthday dinner party that wasn’t fancy dress

Kim Kardashian has suffered through what could be one of the most embarrassing social faux pas: She turned up to a party thinking it was fancy dress when it was very much not.

In a moment that would see most people wishing they could be swallowed up by the Earth, the reality TV star rocked up at Tracee Ellis Ross' 50th birthday party in full costume.

Everyone else was dressed in regular clothes.

But we have to give it to Kim as she took it in her stride, posing alongside the birthday girl for a quick selfie that wound up on Instagram with the caption: "That time I showed up to a birthday dinner in full costume when it wasn't a costume party!"

Kim was dressed as X-Men's Mystique, which means she arrived head-to-toe in blue with the exception of the character's slicked back red hair.

So we're talking all blue face paint and a skin-tight latex blue bodysuit.

We can only presume that the 42-year-old media mogul had donned the impressive costume for a photoshoot earlier in the day and decided to roll with it into the evening.

Well, that semi-backfired.

Kardashian had posted photos to social media earlier in the day that showed her at a Halloween-styled photoshoot with Olivia Pierson as Magik and Natalie Halcro as Selene.

And the girl squad had it going on, so maybe we'll see Kardashian slip into the blue suit again to take up the official role in any future X-Men films.

Probably not, but Jennifer Lawrence and Carmen Elektra - who have both played Mystique in previous films - should be on high alert.

Kim also shared a selfie from later in the evening with Sean 'Diddy' Combs dressed as the Joker.

It's unclear if they both attended the 50th birthday bash or if they were at a Halloween party, but either way they nailed the costume assignment.

Some other celebrities, however, did not.

Machine Gun Kelly and Megan Fox have found themselves at the sharp end of a huge backlash over their Halloween costumes.

Instead Kelly - real name Colson Baker - and Fox decided to get dressed up as drummer Tommy Lee and Baywatch star Pamela Anderson, which ruffled feathers for glorifying an abusive relationship.

They then doubled down on. the controversy by offending a whole religion by dressing as a Catholic priest and a worshipper.

The images posted to social media showed that Fox decided to go the more provocative costume route by donning fishnets, a collar, a dog lead, and black, wet look lingerie.

Yikes.