Downton Abbey's Allen Leech has revealed that while he generally goes unnoticed in the street, it's a different story on Mondays after the period drama has aired the night before.
The Killiney native said he gets stopped by fans more than he used to, but he's still able to take the Tube in London without being recognised.
"When I get the Tube on Monday morning after the Sunday night episode, people recognise me or do that double-take thing, thinking we hung out at a party once," he said.
"And they kind of say hello, but they don't know why they're saying hello. As we move from station to station, they realise maybe we didn't meet at a party and they were watching Downton last night, and that's always fun to watch."
Allen (33), who stars in new movie The Imitation Game with Benedict Cumberbatch and Keira Knightley, said the Sherlock star is mobbed by fans everywhere he goes.
"I actually like it, not being recognised too much. Walking around with Benedict, it's very hard for him to go unrecognised anywhere," he said.
"At the Toronto Film Festival, I was in the car ahead of him and I felt like a warm-up act for The Beatles. The girls went insane."
While Allen's character on Downton, chauffeur-turned-toff Tom Branson, is leaving the show after the Christmas special to pursue a new life in America, he hopes he can return to the TV smash hit in the future.
"As an actor, I always like to see a way I can come back, so I wouldn't like my time in Downton to end in death," he said.
"In all honesty, I would love for the family to understand it was his time to leave and for him to be in a positive position to move forward."
Downton is Allen's biggest role to the date, and he admits he has learned a lot about his profession from his time on set.
"The biggest thing is that I've learned much from my peers, honing my craft," he said.
"And, you know, you can't sit around the dining room table for three years with Dame Maggie Smith and not learn how to deliver a good put-down.
The Imitation Game was released in Irish cinemas yesterday.