Fans were certain Robin was between JLS star Aston Merrygold and X Factor singer Olly Murs.
Other guesses as to who was behind the majestic Robin included Nicky Byrne and Jake Wood.
On hearing the news one fan said: “@astonmerrygold just knew it was you! Congratulations you were amazing.”
Fans were thrilled to see former contestants Sophie Ellis-Bextor, Mel B, Glenn Hoddle, Martine McCutcheon, John Thomson, Lenny Henry, Morten Harket, Sue Perkins and Gabrielle return.
All 12 contestants gave a star-studded performance to gear fans up for the final big reveals.
The official Twitter account teased the final episode, saying: “Tonight, no more secrets. The truth is revealed.”