'Bridgerton' Season 3 cliff-hanger leaves fans wanting more. Expect Part 2 to be 'a steadily rising arrow of tension,' showrunner says.

Warning: Spoilers ahead for Bridgerton Season 3, Part 1

It was years in the making: Bridgerton’s Penelope Featherington (Nicola Coughlan) and Colin Bridgerton (Luke Newton) finally crossed the threshold from platonic friends to passionate lovers at the end of Season 3’s jam-packed first half. The closing minutes are about as romantic as it gets, though in classic Bridgerton fashion, the final episode of Part 1 ends on a cliff-hanger.

“It’s nice for people to be able to have some time to regroup after the first four episodes and also to savor the season,” Bridgerton showrunner Jess Brownell told Yahoo Entertainment. “There’s definitely a little bit of organized chaos at the end of Episode 4, so people might need a little break after that.”

After Penelope’s suitor, Lord Debling (Sam Phillips), takes himself out of marriage contention due to her affections lying elsewhere, she tearfully races out of the ball and heads home in her carriage. By this point, Colin has realized his feelings for her, stopping the carriage and joining Penelope for a heart-to-heart conversation.

Colin confesses he’s deeply in love with Penelope, which leads to her expressing that she wants to be more than friends. Things quickly heat up, leading to a steamy sex scene in the carriage, which is considered one of the couple’s spiciest moments from author Julia Quinn’s book, Romancing Mister Bridgerton.

When the carriage abruptly stops in front of the Bridgerton house, Colin stuns Penelope with a sudden proposal: “For God’s sake, Penelope Featherington. Are you going to marry me or not?”

How’s that for a cliff-hanger?

“It was really important for us to have Colin's feelings for Penelope start to develop before Lord Debling came onto the scene, which is why Debling doesn't become a bigger character until Episode 3,” Brownell explained. “However, his appearance does put a time clock on things for Colin to figure out the feelings that had already been developing.”

She considers their first kiss in Episode 2 as the turning point for Colin to begin to face the feelings he’s been having for a while.

“The first kiss is a moment where his feelings become more recognizably different to him,” Brownell said. “If you look at the story, the seeds for his feelings changing are planted in him realizing that Pen is upset at him because Colin often takes Pen for granted. When suddenly she might not be there anymore, subconsciously he’s going, ‘I don’t like that. I like having her in my life.’ He might not be in touch with what those feelings are, but that’s the moment deep down he realized, ‘I really care for this person.’”

The palpable tension in the buildup to Penelope and Colin’s carriage caress was surprisingly inspired by HBO’s Euphoria.

“When we were planning Episode 4 and everything leading up to the carriage scene, I was rewatching Season 1 of Euphoria. There's an episode that's set almost entirely at a carnival, and the tension in that episode rises incrementally. There's this soundtrack that ramps up piece by piece and makes you feel all this anxiety,” Brownell explained. “I was listening to that soundtrack on repeat when we were crafting this section of the episode, and I loved the feeling that things just keep getting crazier and crazier, and the dance set piece was a great way to emphasize that.”

Brownell's objective was for viewers to feel that buildup.

“You have Pen dancing with Debling and all of a sudden then here comes Colin and then here comes Cressida [Cowper], and things keep building and building,” she explained. “It's very much intentionally chaotic, leading to this final moment where Colin admits his feelings.”

Brownell said she was “excited and optimistic” writing Penelope and Colin’s swoonworthy carriage encounter, mainly because “Nicola and Luke, as actors and as people, have a great friendship, and so much of this story and this season is about love that’s based on friendship.

“It was thrilling to write a different kind of sex scene — a sex scene in which there’s real tender openness and depth,” she continued. “There’s laughter. We don’t often see laughter in sex scenes on television, and I think there’s real beauty in that.”

In the book, Colin’s marriage proposal comes after he learns Penelope is Lady Whistledown. At this point in the series, only Eloise (Claudia Jessie) is aware of Penelope’s secret.

“We felt like we’ve already played the story of the queen hunting for Whistledown for two seasons, and we felt like we needed a rest from that storyline a bit,” Brownell said of the switch-up. “That will become a bigger thread in the back half.”

When Part 2 drops on June 13, “Polin,” as fans affectionately refer to the couple, will be in their honeymoon phase. With Penelope’s Lady Whistledown secret looming over their heads, it will likely create romantic turmoil when Colin does eventually discover her secret.

“Narratively, it was really useful for us because it is this giant secret that’s hanging over this new romantic pairing, but what that allows us to do in the back half — as viewers will see — is spend more time in the love bubble between Colin and Penelope,” Brownell said. “In past seasons, we’ve had to create direct conflict between the couple, but we didn’t have to do that as much this season, because as soon as that secret lands, it’s going to upend everything.”

The last four episodes of the season promise to be even more dramatic.

“The back half is really an upside-down world of the front half,” Bronwell teased, hinting that there’s “plenty of plot” for them to still cover.

“If the front half is rom-com and lightness, playfulness and awkward banter, the back half is a steadily rising arrow of tension. That little bit of chaos that you saw at the back of Episode 4, it keeps on ramping up in the back half,” she said.

Bridgerton Season 3 Part 1 is streaming on Netflix. Part 2 starts streaming on June 13.