It's the most divisive storyline in Love Actually: is Mark's crush on his best friend's new wife – and his stunt with the cards in the doorway – romantic or creepy? Is this the work of a charming lovestruck man, or a sad stalker who doesn't understand boundaries?

Now actor Andrew Lincoln has revealed he had those doubts before he even filmed the scene, which has become one of the 2003 movie's best-known moments.

“My big scene in the doorway felt so easy. I just had to hold cards and be in love with Keira Knightley." he told EW. "And that was my own handwriting on the cards, thank you for noticing.

"But I kept saying to Richard [Curtis, the film’s creator], ‘Are you sure I’m not going to come off as a creepy stalker?'”

The scene sees Mark (Lincoln) turn up at the door of his best friend Peter (Chiwetel Ejiofor) and his new wife Juliet (Keira Knightley), who has recently realised that Mark's got an impossible and totally inappropriate crush on her.

Juliet comes to the door, where Mark plays carol music on his portable CD player ("say it's carol singers") and silently holds up a series of handwritten placards. "To me you are perfect," he writes.

“In one of the most romantic movies of all time, I got to play the only guy who doesn’t get the girl,” Lincoln complained. “The story is set up like a prism looking at all the different qualities of love. Mine was unrequited. So I got to be this weird stalker guy.”

Looking back, Curtis said: “Retroactively, I’m aware that Andrew’s role was on the edge. But I think because Andrew was so openhearted and guileless, we knew we’d get away with it.”

The famous (infamous?) placards made a comeback for Comic Relief last month, popping up in the Red Nose Day Actually skit as the cast reunited 14 years later. But this time, everyone was doing it...