Newton tells PEOPLE that he and Coughlan discussed “how gentle” Penelope and Colin “would be with each other when it’s the start of something and where we can take it from there”

The Bridgerton carriage scene may have gone viral but for Luke Newton and Nicola Coughlan, it was important to keep the show’s much talked about steamy scenes true to their characters.

Ahead of the release of the second part of season 3, Newton — who plays Colin Bridgerton on the hit Netflix series — tells PEOPLE that “ultimately the goal was for it to seem really authentic to those two characters.”

“We just wanted to honor that because people have a lot of love for their relationship, and we wanted to keep it really true to that,” he says in a joint interview with Coughlan, who plays his on-screen love Penelope Featherington. “So we would have discussions about how their first encounter would be and what the intimacy would be like, and if it would be, and we talked to the intimacy coordinator even [about] the intensity of the scene.”

Newton, 31, adds that he and Coughlan, 37, discussed “how gentle they would be with each other when it’s the start of something and where we can take it from there.”

Coughlan echoes her costar, saying, “I think what’s really beautiful about this season is, the intimacy stuff feels very real.”

“It feels very grounded in two people that are not trying to sort of, that they’re awkward in front of one another, this and that, and all of a sudden they become like letharias in the bedroom and whatever, they get to be intimate together in a very real and beautiful way, and I think that’s what makes it so affecting,” she explains. “In those intimate moments, they find moments to laugh and you see them figuring it out and doing it together, and I love it.”

For her part, Coughlan also reflects on “playing a character that doesn’t know what sex is” before embarking on a friends-to-love romance with Colin, which is detailed in the fourth Bridgerton book, Romancing Mister Bridgerton.

“Even when we had the first kiss, they had to say to me, you can’t seem like you kissed someone before, which is like, okay, yeah, because even it’s hand placement, since it looks a little too mature and you’re like, okay, pull it back, she’s never done this,” she recalls.

Coughlan previously teased that things got heated during the steamy scenes between her and Newton. She also shared that they broke a piece of furniture while filming a sex scene, and found the filming process “really funny.”

“We would be like, in between scenes, and they were like, ‘Do you wanna get up and put your clothes on?’ We’re like, ‘We’ll just chill here.’ Like, in under the blankets,” she recalled during an interview on SiriusXM Hits 1 in April. “But then we have the advantage of knowing each other for years.”

The first part of Bridgerton season 3 is streaming now on Netflix and part 2 drops on June 13.