"They are no longer dating. It was really a location challenge," a source tells E! News. "She has been in Europe shooting "Game of Thrones" and he is based in California, so it was hard to make it work despite the distance. They have remained friends."
The comedian, 39, and the Mother of Dragons, 25, were first seen as a pair in September of last year. Prior to the Oscars hosting gig, the "Family Guy" creator gushed about girlfriend Emilia, without cracking jokes about seeing her boobs on TV.
"She is an incredibly kind, supremely talented person, and one of the hardest-working people I have ever met," he told Entertainment Weekly.
Clarke made her debut as Holly Golightly in the Broadway revival of Truman Capote's "Breakfast at Tiffany's" Wednesday night. Although the audience gave the show a standing ovation, Clarke's performance was panned by critics who said she was "miscast."