U.S. actor, writer and producer Seth MacFarlane is dating British actress Emilia Clarke, sources told UsMagazine.com Tuesday. "It's been going on for a few months," an insider said. MacFarlane, 38, is best known as the creator of the animated series "The Family Guy." Clarke, 24, is a cast member of the HBO fantasy series "Game of Thrones." MacFarlane "wants someone he is attracted to but who can have a good time and enjoy his success with," the source told UsMagazine.com. "He's actually also a 'Game of Thrones' fan!"