Richard Madden's mum introduces him to people as "Little Dick".
The 'Bodyguard' star has revealed his mother cannot resist the joke when she is speaking to pals, and she even calls his dad namesake "big Dick"
He said: "She loves it. It is her favourite gag. My father is also called Richard, which translates as big Dick and little Dick. Thanks mum."
The former 'Game of Thrones' star has become a household name since appearing on the HBO fantasy series as Robb Stark and then as personal protection officer David Budd in 'Bodyguard'.
But the 32-year-old hunk admits he was a "late bloomer" because he spent a lot of his formative years looking like a "big potato".
Speaking on 'The Late Late Show', he added: "I was a bit of a late bloomer. I just looked like a bit of a potato for most of my younger years... a big potato."
Richard recently revealed he is to enter talks with 'Bodyguard' creator Jed Mercurio about a second series of the drama show, which featured Keeley Hawes as Home Secretary Julia Montague, and he has some ideas about how the programme can progress.
He said: "I'm going to meet Jed in a couple of weeks, to have a chat and see what's in his brilliant brain.
"So I'm like, what can happen next? You know, with David. Because he had a hell of a couple months there. Where do you go with this guy?
"I also thought, maybe it's going to be like 'American Horror Story' where, in the second series, it's a whole different incarnation of it, and I'm a royal and Keeley is on my protection team.
"And you get all the rest of the actors back, and we all do different things. But who knows what's in Jed's mind. I'm very keen to hear.
"Also I think, you know, David Budd, he walks about London with a bomb on. I mean, everyone definitely knows his face now. He can't really slip back into police work again. What's his life like after that?"
Tagged in Keeley Hawes Richard Madden