'Bridgerton' star Nicola Coughlan says she was 'really crying' during confrontation in finale: 'Made me feel sick to my stomach'

• Warning: Spoilers ahead for the season-two finale of "Bridgerton."
• During the season finale of "Bridgerton," best friends Penelope and Eloise get in a huge fight.

"Bridgerton" star Nicola Coughlan told E! Online that she was "really crying" when she filmed the fight with her on-screen and off-screen friend Claudia Jessie.

In season two, which premiered last month, Coughlan's character Penelope Featherington tries to keep the secret that she's Lady Whistledown from her best friend Eloise (Jessie) and the rest of the town after her identity was revealed to the audience in the season-one finale.

In the season-two finale, Eloise finally works out the truth after Lady Whistledown had ruined her reputation and Penelope manipulated her to end her budding romance with a working-class pal called Theo (Calam Lynch).

The pair get in a huge fight and, by the end, it seems their friendship is over — at least for now.

In an interview with E!, Coughlan recalled being "super nervous," which resulted in crying real tears during the scene.

"Friendship breakups are just so horrendous," she said. "To film that scene was really harrowing and actually like, made me feel sick to my stomach."

She added: "It was just awful."

Coughlan also said that she and Jessie predicted there would be a fight like this early in production.

"We had an inkling that this was going to happen from the first couple of episodes," she said. "Because there was one line, where Penelope says to Eloise, 'You cannot lie to me!' And I went, 'Why is she saying that?' And I sort of questioned it and [the writers] said 'No, please say it. It's important because of later on.' And we both went, 'Oh, no. Oh, no. This is bad.'"

Earlier this year, Jessie told the Guardian that she and Coughlan became close after the "Derry Girls" actress accidentally stabbed Jessie with her parasol during their first scene together.

"She drew blood," Jessie recalled. "Nicola had heels on and kept falling over. I tried to catch her and the silver spokes of the umbrella went bosh, straight into my hand. I managed to keep it away from my costume but bloodied my white glove. It was a blood oath. That's why we're so close now."

Jessie also told Elle that she was "so pleased" when she was given the script for the episode where Eloise finds out the truth.

"I think Eloise probably wants to be Lady Whistledown a bit, so that's why it's so interesting," the 32-year-old actress said.

She added: "Every time they called cut, we'd have a little cuddle. Because we were nervous for it. We were nervous. We were talking about it for weeks ahead of shooting."

Bridgerton season two is currently available to stream on Netflix.