Rose Leslie and Kit Harington have a FaceTime romance

Actors Rose Leslie and Kit Harington rely on video calling app FaceTime to keep the romance alive in their long-distance relationship.

The couple has been romantically linked since 2012 after meeting on the set of hit fantasy series Game of Thrones. The stars only went public with their relationship in April, 2015, but have been open about their affection for one another ever since, and the Scottish actress admits their various work commitments often keep the pair apart for weeks on end.

"It's kind of an embarrassment of riches whereby both of us are working. It's a wonderful thing to be involved and to be busy, but yes, I suppose we make it work, FaceTime is a must," Rose said, admitting the frequent calls often leave her with a costly phone bill at the end of each month.

As well as starring in Game of Thrones as wildling Ygritte, Rose also found fame playing Gwen Dawson in Downton Abbey. The show went on to become one of the most successful period dramas ever, but Rose admits she had no idea just how popular it would become.

"At that time I was very excited just because it was a gig for six months," she said. "I'd never been employed for that amount of time. But certainly I knew that we were onto something great, just because of (leading stars) Maggie Smith and Hugh Bonneville. You're like, 'Well you're always going to be surrounded with good drama and brilliant actors.'"

She added: "I think even when I arrived as a newbie, particularly in Game of Thrones, I was unaware of the phenomenon that it would become. It's amazing to be a part of both those shows."