A teen's mission to secretly use her mum's fake tan just backfired most spectacularly.

When this mum discovered her teenage daughter was using her beauty products, she decided to get revenge in the best possible way: by sharing the fail online for all to see.

Katie O’Connor, 31, couldn’t help but share her daughter’s fake tan mishap with the world, posting an image of her foot – which had been stained orange – on image sharing site Imgur.

“This, Ladies and Gentleman, is my foot a week after I came home after a 15 hour shift, removed my shoes and discovered it had turned a lovely deep shade of terracotta,” she wrote.

"My 14 year old daughter promises that she hasn't used the more than likely out of date fake tan that's been sitting at the bottom of my wardrobe for about a year now even though her legs resemble lightly toasted wotsits while the rest of her is practically albino (sic)," Katie wrote.

"She swears to god that she didn't use my socks to apply it either, and she most definitely didn't put said sock back in my f***ing drawers. Somehow I don't quite believe her ????"

Katie said that she had been "scrubbing, soaking, using baking soda, peroxide" to try and rid her foot of its unusual orange glow.

So far, "it's still a hideous bastard orange".

"Someone please tell me what to do before it starts building walls and picking on Mexicans," she wrote.

LISTEN: Zoe Foster-Blake’s beauty advice for busy women.

As is the way online, some offered up some genuinely helpful suggestions.

"Lemon juice, baking soda and something scrubby," wrote one, while another suggested a heavy dose of exfoliator.

Other recommendations weren't so helpful, but they were hilarious nonetheless.

"This may be a long shot but try to surround it with peaches. I think they call it impeachment," wrote one.

What has been your biggest beauty blunder? Tell us in the comments below!