Blake Lively has been left giddy with excitement after Emma Bunton praised the Baby Spice costume she wore to a Spice Girls concert back in 1997.

Over the weekend Twitter user Bria Madrid shared a throwback snap from when she was five years old which showed her posing with a fellow Spice Girls fan at the concert who was dressed like Emma, who she only recently realised was 'The Shallows' actress.

She captioned the photo: ''Found a picture when I was 5 at my first concert. #SpiceGirls and took a picture with a girl dressed up as Baby Spice who I just realised now was @blakelively (sic)''

The tweet was spotted by Blake, 30, who retweeted the post along with the message: ''My secret is out...''

Blake then shared the photo on her Instagram account and thanked Bria for sharing the cute image.

She wrote: ''Pretending to be someone else ... since 1997 (Thanks @briaaamadrid for the photo of us at the Spice Girls concert. Sorry - not sorry - I tricked you into thinking I was @emmaleebunton) (sic)''

It was that post which was seen by Emma, 42, and she took the opportunity to praise Blake, 30, for being such a great Baby Spice.

She posted: ''So cute, you're rocking those pigtails @blakelively.''

Blake was blown away to be messaged by her favourite member of the girl group - also comprised of Mel B, Victoria Beckham, Mel C and Geri Horner - and replied to her straight away.

The former 'Gossip Girl' star wrote: ''@emmaleebunton I'm officially (dead). Forever bowing down to you ... I cannot believe you know who I am. This will never be normal... (sic)''