At a press event for “Game of Thrones” Season 7, Gemma Whelan and Alfie Allen chat with Access Hollywood about what it was like when their characters — siblings Yara and Theon Greyjoy — reunited last season. Plus, the two dish on how much fun they have working together. “Game of Thrones” Season 7 airs Sundays at 9 PM ET/PT on HBO.