For a film with many funny moments, it was a scene memorable for its poignancy.
In Love Actually, Emma Thompson played a wife who sobs uncontrollably after she discovers that her husband has bought jewellery for another woman and realises he is cheating on her.
Now, Thompson has revealed that she was so convincing in the 2003 film as a result of personal experience – having her heart "very badly broken" by first husband Kenneth Branagh, as the Daily Mail reports.
Once the golden couple of British cinema, dubbed Ken and Em, they split after eight years together when he began an affair with Helena Bonham Carter.
Thompson, 58, told an audience at a fundraiser for the Tricycle Theatre in northwest London on Sunday that every woman could relate to the heartbreak her character felt in Love Actually, as they could understand the pain of suspecting their husband has been unfaithful.
"That scene where my character is standing by the bed crying is so well known because it's something everyone's been through," she said.
"I had my heart very badly broken by Ken. So I knew what it was like to find the necklace that wasn't meant for me.
"Well it wasn't exactly that, but we've all been through it."
At the same event, Thompson spoke about the #MeToo protest against sex harassment.
Having once revealed that when she was nine a 45-year-old magician forced her to kiss him, she told how in her youth she was constantly fending off unwanted advances by older men.
"Our industry, because part of what we have as actors, we have an attractivity level, and that's something that can get very dirty and grungy," she said.
The actress also told the audience: "I feel like I look my age and I don't mind that. I put concealer under my eyes, but I like looking my age. I'm 58, I accept that.
"The key to the spirit of youth is curiosity. If you're curious you feel alive. That and not being poor. Being old is heaven."
Thompson and Branagh, now 57, fell in love when they starred as newlyweds in the BBC drama Fortunes of War in 1987.
They married two years later and appeared together in films including Peter's Friends, Dead Again and Much Ado About Nothing.
Branagh and Bonham Carter, who is seven years younger than Thompson, are said to have started an affair in 1994 while filming Mary Shelley's Frankenstein.
The following year, Thompson and Branagh filed for divorce, claiming hectic work schedules had led to the breakdown of the relationship. Branagh and Bonham Carter dated until 1999.
Thompson married actor Greg Wise, with whom she has two children, in 2003.
Branagh married art director Lindsay Brunnock the same year. He was knighted in 2012.
In 2013, Thompson revealed that she had "made peace" with Bonham Carter.
Discussing Branagh's infidelity, she told The Sunday Times: "I've had so much bloody practice at crying in a bedroom, then having to go out and be cheerful, gathering up the pieces of my heart and putting them in a drawer.
"That is ... all blood under the bridge. You can't hold on to anything like that. I just think ... pfft.
"It's pointless. I haven't got the energy for it.. Helena and I made our peace years and years ago ... she's a wonderful woman."
The two's similar "slightly mad and a bit fashion-challenged" traits were what made Branagh fall for them, she suggested.