Fabien Frankel believes Nikolaj Coster-Waldau thinks he is "crazy".
Fabien Frankel has had some memorable celebrity encounters
The 30-year-old star met the Danish actor - who is best known for playing Ser Jaime Lannister in 'Game of Thrones' - months before prequel series 'House of the Dragon' premiered and was excited to tell him he was also part of George R.R. Martin's fantasy world, but was too drunk to make much sense.
Fabien - who plays Ser Criston Cole in the HBO fantasy drama - recalled to 'Entertainment Tonight': "I met Nikolaj Coster-Waldau in a bar in L.A. about six months before it was coming out.
"I kinda came up to him, I was quite drunk, and I was like, 'I'm in the show. I'm kind of like you in a weird way.' I think he thought I was crazy and not telling the truth. He was very, very nice. He's also so tall and I was like, 'Wow, hi Nikolaj.'"
And Nikolaj isn't the only famous face Fabien has had a "crazy" encounter with, as Tom Holland said something "really nice" to him in the gym.
He recalled: "He just came up to me, I was in the gym, and he was like, 'Love the show, man,' and he fist-bumped me.
"I was like, 'Thanks, Spider-Man.' That was really nice."
'Vossi Bop' hitmaker Stormzy is also a fan of 'House of the Dragon', much to Fabien's delight.
He said: "Stormzy, who is a very famous British rapper, who is like a hero in England, I met him and he loves 'House of the Dragon', and I was incredibly overwhelmed.
"He also had just given one of the best speeches I've ever heard at the GQ Man of the Year Awards, and then I saw him.
"Me and Milly [Alcock] were going upstairs and then we ran into him.
"He was like, 'Woah, woah, woah, woah!' And we were like, 'Woah, woah. What do you mean?' Anyway, I told that story badly, but it was amazing."
The actor has a lot of fun filming the show and admitted he and his co-stars can be "very mischievous".
He said: "I got to work with Freddie Fox, who plays Ser Gwayne Hightower. I think fans are gonna love him or hate him, but I think they'll love him.
"Genuinely, it's a lot of laughter. We've got a very giggly cast... It's a very mischievous set.
"Freddie Fox ran... full speed from his horse about 500 meters in the middle of a take for no reason, because I just asked him to."
Tagged in Tom Holland Nikolaj Coster-Waldau Stormzy