Britney Spears has extended an invitation to Prince William and Kate Middleton to see her Femme Fatale tour when it hits London in October.

The pop princess – who famously admitted to having a crush on the future king earlier in the noughties, and is even rumoured to have exchanged emails with William back in 2002 – said it would be "crazy and cool" if the royal couple attended her upcoming shows at the O2.

However, despite claiming to be a big fan of the Duke and Duchess of Cambridge, Spears admitted that she did not get chance to watch William and Kate's wedding in April. "Unfortunately I did not get to watch the wedding, but I heard it was beautiful," she said.

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It was during the recording of an interview for ITV1's Frank Skinner Show in 2002 that Spears claimed she and William had emailed each other and even discussed meeting up. But she revealed the rendezvous "didn't work out".

Spears has been officially dating her former agent, Jason Trawick, for over a year, but she was first rumoured to be secretly seeing him back in 2009. Trawick resigned as her agent last year to concentrate on their relationship.

The Femme Fatale tour hits the O2 on October 27 and 28.