BASHFUL Prince William lasted for just 30 ­seconds of his first dance with Kate – after asking singer Ellie ­Goulding to switch quickly to a faster number.

Rising star Ellie, 24, ­serenaded the happy ­couple with her version of wedding guest Elton John’s 70s classic Your Song.

William and Kate took to the floor arm in arm for their slow waltz at 10.30pm, cheered by the 350 guests at the evening reception.

But self-conscious ­Wills had earlier requested Ellie speed on “to a faster one so others can join in”.

Later, he and Kate raised the roof with a ­hilarious ­version of You’re The One That I Want from Grease.

With William dressed in a black tuxedo and bow tie and Kate wearing her ­stunning strapless white evening dress, they strutted and sang their way through the John Travolta and ­Olivia Newton-John classic.

Guests were on their feet whooping, clapping and cheering as the beaming newlyweds let their hair down – and showed off fun-loving personalities.

One bleary-eyed guest – who left the party at 3.15am – said: “The Grease number brought the house down.

“They stood holding hands in the ­middle of the dancefloor grinning, then suddenly the opening bars of the song came booming out.

“The reaction was just brilliant. Everyone started clapping to the music.

“Wills and Kate began dancing around, pointing at each other and mouthing the words. It was ­hilarious.

“When the song finished, they ended up in each other’s arms with massive smiles on their faces.

“Everyone was cheering wildly, whooping and they did a bow to each other.

“After that, the ­dancefloor filled up and the party got going properly. It was a fabulous night. The kind of night you ­never forget.”

Singer Ellie stepped in after one half of a ­Bollywood duo set to perform suffered a knee injury.

She said: “It was an ­amazing honour to be asked by Kate and William to perform at their party. The atmosphere was incredible and it is a night I will ­never forget.”