[BBfanUSA]

Actually Jessie was on a US results show and she sang Domino with one of the teams performing backup and they mentioned she was a UK coach.

So it's two versions helping each other out.

I'm thinking the surprise is Justin Beiber. Here's why, When he showed up to show a sneak peek of The Boyfriend Video on the US. Justin was talking to Adam about a supergroup thingie as he showed up and I imagine that Will.I.Am and Jessie J are friends with Adam who can easily get the help of someone, probably Beiber.

(That night it was announced that the first live performance of Boyfriend would be at the finale of the US version)