Taylor Swift indulged in an unlikely threesome last night (November 26) as she sang on stage with Bon Jovi and Prince William.

The collaboration happened at a charity event at London's Kensington Palace in aid of homeless charity Centrepoint.

William, who is a patron of the charity, provided backing vocals alongside Swift as they joined Bon Jovi in a rendition of the band's classic 'Livin' on a Prayer'.

Speaking before her performance, Swift said:

"It's positively magical here. There are fairy lights and there is fake snow falling from the sky and everything is just gorgeous. I am just very lucky to be here. I don't think I have ever played in a palace before. So it will be really wonderful. This evening is so special...It is for a charity that as well as being very important to Prince William is also very important to me."

She later posted on Twitter a photo of the trio singing, along with the caption: "OHHHHHH! LIVIN ON A PRAYERRRRR".

Other attendees on the night included Tinie Tempah and James Blunt.