The actor, who played Bran Stark in all eight seasons of the show, has revealed the main stars no longer use the giant group WhatsApp chat, set up so everyone on the show could keep in touch when they weren't filming.
"It's dead at the moment. It's petering out," he told Britain's Daily Mirror newspaper at the Q Awards in London on Wednesday, October 16 night, adding that although certain cast members do bump into each other from time to time, they are often too busy to chat.
The news will come as a shock to fans, after the stars of the series lamented the show's final episodes over the summer, and appeared overjoyed to reunite at the 71st Primetime Emmy Awards last month.
And actress Lena Headey recently insisted the chat is still a "daily pile-on," telling British newspaper The Observer, "It's hilarious. You can tell who’s been drinking on that one."
"Game of Thrones" came to an end in May, more than eight years after it debuted.