Yep, lucky Dame Maggie Smith is on the receiving end of a Clooney smooch when he drops into the Grantham-Crawley world as part of a Text Santa special.
A teaser of the storyline was revealed by Downton Abbey actress Laura Carmichael - who plays Lady Edith - during her appearance on ITV's This Morning earlier today.
Usually storylines for Downton are kept firmly under wraps, but Laura was allowed to reveal a little bit about Mr Clooney's appearance...
"There is a very brilliant moment with Maggie and George - and I don't know if I want to give away any more than that really - but Maggie does a very comedy fall - George plants a kiss and Maggie ends up on the floor, it's wonderful. He was hilarious!"
We can't wait!
Laura also admitted the cast weren't even sure George would really join them on set until it happened and, as you'd expect, his arrival caused frenzy among everyone!
"It's amazing and we didn't even know if it would actually happen until he turned up! We were filming away and then heard 'he's here, he's here, he's arrived'... But he was wonderful and so brilliant and I'm very excited for everyone to see it."
It's thought George's appearance came about because of his friendship with Hugh Bonneville, who plays Lord Grantham. George and Hugh appeared together in recent movie The Monuments Men.
Meanwhile, the fifth series of Downton starts this Sunday, 21 September at 9pm on ITV.