Show boss and head judge Simon managed to secure Adele to sing on Sunday's results show, and he admits he really struggled to keep it a secret.
Simon literally couldn't hide his excitement about the singing sensation as he spoke to Reveal at the X Factor red carpet event at Hilton London Wembley.
"It took me a while to make up my mind whether we really wanted her or not," Simon joked. "Are you kidding?! When we got he news, and I had to keep it quiet last weekend, it was like, this is the best news I've had all year!
"She absolutely is going to cap of what I hope is going to be an amazing weekend."
Also taking to the stage on Sunday's results show will be Coldplay and X Factor alumni One Direction.
"Actually, it's really the best of British," continued Simon. "It's Coldplay, it's One Direction, it's Adele, it's the biggest artists in the world. It's going to be sensational."
The X Factor Final: The Results - Sunday at 8pm on ITV.
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