By James Hibberd
Updated March 31, 2014 at 12:19 PM EDT
Macall B. Polay/HBO

In Game of Thrones season 4, Jaime Lannister is reunited with his long lost love — who just happens to be the Queen Regent and his twin sister. But don’t expect Jaime and Cersei (Lena Headey) to make a quick return to the sneaky, incestuous ways we last saw in season 1.

“For him, it’s been a very traumatic trip,” says Nikolaj Coster-Waldau, who has ditched his scraggly beard and returned to Jaime’s clean-cut look now that his character is back in King’s Landing. “But he’s been wanting to get back to this woman for the duration of his trip. You want to just go back to the way it was. But it’s not that easy. A lot has happened in her life as well.”

Definitely traumatic. Jaime was imprisoned and had his right hand chopped off last season, leaving him far less able to protect himself (or the king, for that matter, as he’s a member of the royal Kingsguard). While he’s perhaps gained more inner strength, expect Jaime’s physical weakening to be a turn off for Cersei, who has always relied on her brother’s alpha male status. “In her mind, he was the strongest soldier, the strongest man and he could always protect her,” he notes.

Having said that, Coster-Waldau adds that you don’t need to see any new episodes to know there have been hints that this relationship was already uneven. “I think he loves her more. It’s always been unbalanced, and that’s never good,” he says. “Most of us have been in that situation where you’ve been falling in love with somebody who didn’t feel the same way. It’s not a nice situation. We did this panel and Lena said something interesting. She said at a deep level, she wants to be him. She likes the game of thrones, but her life is about doing what her dad wants her to do.”

And then there’s the other woman in Jaime’s life, Brienne of Tarth (Gwendoline Christie), his former captor turned ally. Expect Brienne to try and hold Jaime to his pledge to ensure the safety of Catelyn Stark’s daughters, which is a tad tricky now that one of them is married to Jaime’s brother Tyrion (Peter Dinklage).

“There’s a moment where they come back and he’s like: ‘What happened didn’t really happen. Can’t I just become what I was before?'” he says. “And she’s like, ‘What about that promise?’ A year ago he would have said ‘shut up and go away,’ but now it’s like, ‘I guess I have to deal with this.”

But those holding hopes for actual romance between Brienne and Jaime shouldn’t expect to see any physical connection anytime soon. “I don’t think he’s aware of any romance,” he says. “On a fundamental level he respects and cares for this woman. I don’t think he’s thought of it.”

Coster-Waldau grins. “He’s a monogamous man.”

EW’s Game of Thrones Pre-Season 4 Coverage. Catch up on what you’ve missed:

‘Game of Thrones’ handy snarky season 4 map explains where everybody is

‘Game of Thrones’: This showrunners Q&A will get you really excited for season 4

‘Game of Thrones’: Jack Gleeson reveals the meanest thing he’s ever done

‘Game of Thrones’: Lena Headey on Cersei’s twisted love life

‘Game of Thrones’: Sophie Turner takes six Sansa questions

‘Game of Thrones’: Nikolaj Coster-Waldau on Jaime’s season 4 women trouble

‘Game of Thrones’ season 4 is Jon Snow’s biggest, talkiest yet

‘Game of Thrones’ Maisie Williams teases Arya’s dark season 4

‘Game of Thrones’: Ygritte is super pissed in season 4

Peter Dinklage talks ‘Game of Thrones’ season 4: Tyrion’s journey, ignoring Twitter, nude scenes

‘Game of Thrones’ two more ‘final’ trailers

‘Game of Thrones’ showrunners sign on for two more seasons — EXCLUSIVE

‘Game of Thrones’: How Pedro Pascal landed season 4’s coolest, sexiest new role

Game of Thrones’: See Jaime Lannister’s new golden hand — EXCLUSIVE

Game of Thrones’ producers: George R.R. Martin’s secret ending is ‘absolutely’ satisfying — EXCLUSIVE

Game of Thrones’ team: 7 seasons is the plan

Still to come: Once the season starts we’ll have our popular recaps (find them here) and post-episode interviews with cast or producers each week.

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