And Kit - who recently got engaged to his partner and former on-screen love interest Rose Leslie - says the cast and crew of the drama are forbidden from even telling people when they're filming, as the show bosses want to keep the production as top secret as possible, in order to prevent plot rumours spreading.
Kit added: "[I was told], 'Don't tell them when you're filming. Don't take pictures in Belfast. Don't do all of that'. It's on lockdown!"
Despite shedding a tear at the thought of his time in the fictional land of Westeros coming to an end, Kit previously admitted part of him was pleased to be finishing his run on the show, as it will give him the time to pursue other projects.
He said: "It will be liberating, just the thought of having a whole year free - you shoot for six months, but half of the projects you might want to do will have started shooting before that six months is over.
"There's a lot of things you can't do. I'm looking forward to finishing, and eight years is the right amount of time. I wouldn't want it to go on any longer than it has. I have other ideas I'd like to look at producing."