"No one drinks a goblet of wine like you do on Game of Thrones," as Jimmy Kimmel put it on Monday night's episode of Live.
So Kimmel challenged Headey, in character as Cersei, to a drunken Game of Thrones-style insult war.
"That's a lovely tie. It's such a shame it's around a worthless neck," Headey began.
"Thank you for coming today, I know you have a busy schedule doing sex with your brother. It must be exhausting," Kimmel hit back, in reference to Cersei's incestuous relationship with her twin brother, Jamie.
Watch the rest below: