It's Always Sunny In Philadelphia fans got a treat on Sunday night if they were watching Game of Thrones (with 17.4 million other people.)
Rob McElhenney, who plays Mac, made a super fast cameo in the HBO series.
Seriously, if you blinked, you probably missed it.
Yes, that was Rob who got shot in the back of the head by Theon Greyjoy.
Rob is used to hanging out with Dothraki, so this seemed like an easy fit.