Jaws hit the floor when they saw Jennifer Lopez rock up to her 46th birthday party in a very daring see-through black dress.

The superstar, who threw a lavish bash at 1 OAK nightclub to mark the special occasion, looked decades younger in the revealing frock and she managed to throw some serious shapes wearing it.

New photographs from inside the party show her getting cosy with on/off boyfriend Casper Smart before posing with pals and getting wild on the dancefloor and throwing her arms in the air.

She draped her arm over the dancer while leaning up in a pair of strappy heels and he looked like the cat who got the cream, smiling while trying to keep his arms off his missus.

He was wearing some rather tight trousers for the event, no doubt on purpose, and we imagine the snapper didn’t quite know where to look. There’s not a lot that can distract from Jen’s famous curves.

She slipped into one of her most sexiest outfits ever to celebrate her big night on Friday, after debuting a much shorter hairstyle. We approve.

The singer managed to distract fellow guests from the fact that she had turned another year older by wearing the outrageously racy dress.

She posed with pals including French Montana and Natasha Bedingfield in a VIP area before heading out to party. Who knew they were such good pals?

Jen looked like she was having a whale on the time as she hit the dancefloor and showed everyone exactly how to Jenny From The Block likes to party.

In less than five decades the star has managed to conquer everything from the album charts to the Box Office.

These days she’s shooting for upcoming crime drama Shades of Blue where she plays a detective .

Earlier in the day, J-Lo acknowledged the occasion by sharing a throwback snap from her childhood.

The picture, shared with her Instagram followers, featured the songstress as a very happy youngster.