Emmys weekend proved to be a quiet coming out party for the unexpected pair; after hanging out at HBO's after party together at L.A.'s Pacific Design Center, they were spotted leaving together.
Just one day before, MacFarlane and the British beauty (who plays the frequently nude Daenerys Targaryen/Khaleesi on HBO's smash fantasy series) were photographed on an apparent date leaving the Four Seasons Hotel in Beverly Hills.
And on Sept. 17, newly emerged pics show the pair letting loose in L.A.'s Koreatown -- singing karaoke at Cafe Brass Monkey!
On Tuesday -- two days after the Emmys -- the duo were spotted again, arm-in-arm, leaving Mel's Diner.
What's the secret to this unlikely pair? "[Seth] wants someone he is attracted to but who can have a good time and enjoy his success with," the source explains to Us. Bonus? "He's actually also a Game Of Thrones fan!"