Imagine your dream wedding day - the dress looks just how you dreamt it would, your partner turned up (result), your dad cried and now the booze is flowing and suddenly, Katy Perry arrives.

Well, that's what happened on Hayley Rosenblum and Blonie Dudlney when celebrating their special day last weekend.

The pair had a beautiful ceremony, them moved to the reception at St. Louis' Four Seasons Hotel.

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The newly-weds and 300 or so of their guests were getting down on the dance floor when, according to the Kansas City Star, 'all of a sudden a huge group of people came rushing in and they were wearing shorts and T-shirts and jeans and hoodies. They were not dressed in wedding attire.'

The bride's friend Amy Prada spotted Katy Perry in the group and then grabbed Rosenblum pushed her in Perry's direction.

Law student Rosenbaum took the opportunity to boogie on down with the Roar singer, going bum to bum to Pharrell's 'Blurred Lines'.

Thankfully Prada got it all on film.

Perry and her crew stayed for about 10 minutes, taking snaps with guests and the new couple.

Obviously the pair loved that the Swish Swish singer popped by, but we wouldn't recommended trying this for yourself.

'It made the night,' Prada told the Kansas Star, 'The wedding itself was just absolutely stunning, and the bride was beautiful. But that was the icing on the cake.'

These wedding party photos have since gone viral, because, you know, it's Katy Perry crashing a wedding.

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Daisy Murray
Digital Fashion Editor

Daisy Murray is the Digital Fashion Editor at ELLE UK, spotlighting emerging designers, sustainable shopping, and celebrity style. Since joining in 2016 as an editorial intern, Daisy has run the gamut of fashion journalism - interviewing Molly Goddard backstage at London Fashion Week, investigating the power of androgynous dressing and celebrating the joys of vintage shopping.