Coster-Waldau – who famously portrayed Jaimie Lannister in the hit HBO series – revealed that some of his fellow actors were not pleasant to be around in between takes.
While he refused to specify anyone by name, the star told The Times that he was speaking about some of “the older actors” on the show.
Parodying the people in question, Coster-Waldau put on a voice and said: “Oh, it’s too f***ing hot! I’m going to complain about this piece of s***! Where do I sit?"
The Danish actor went on to praise his late co-star Diana Rigg who died aged 82 on 10 September earlier this year.
He said that Rigg, similar to her Game of Thrones character Olenna Tyrell, “had so much bite in a funny way”. He joked: “You just didn’t mess with her", before adding: "You can’t win when somebody is funnier and cleverer than you.”
The 50-year-old continued: “When you work with someone like that, you raise your game.”
Speaking about Tyrell’s famous death scene in season eight, which involved his own character Jamie, the actor said: “That last scene of hers was a great day. That was the only two-hander we had, which was a real privilege.”
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