Everyone who watched The diplomat probably wondered at some point why Hal and Kate Wyler remain married.

“They know each other well,” Rufus Sewell, who plays Hal Wyler opposite Keri Russell’s Kate, tells PEOPLE. “They know what they love and what they hate about each other, and sometimes the things they love are the things they hate about each other, and they hate the things they love about each other. It may be a marriage that is coming to an end, but sometimes a marriage that appears to be coming to an end is in the midst of a change.”

Sewell, 57, says so The diplomat creator Debora Cahn wanted to show that “the seeds of divorce and hate and lust and hating the way your partner breathes is a big part of many long-term relationships.”

“I recently heard her say that the people whose relationships ultimately didn’t work out weren’t because someone tipped someone else. It was because they didn’t like the way the other person inhaled,” says Sewell.

As for the Wylers – who Sewell says use “political arguments as foreplay” – the British actor thinks: “They’re fantastic together and a pain in the ass together, and it’s all part of the same thing.”

In real life, Sewell married actress Vivian Benitez in July. He says he’s portraying someone in a not-so-loving marriage The diplomat hasn’t affected how he views long-term relationships.

“I just tried to see things with my eyes and be really honest about my own descriptions of the world, and not about the descriptions of the world that would be given to me by the media,” he says. “My life experience tells me that when I read this script, it is just beautifully accurate.”

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In season 2 of The diplomatHal relies on Kate to help him physically as he recuperates after being injured in the explosion that occurred at the end of season 1.

“He feels frustrated by the physical limitations and the fact that he can’t be as active and flexible as it felt to me when I was filming it,” Sewell says. “The fact that he has to ask her to help him with even the most mundane personal things – not that they have a problem helping in that way, but he feels like it’s almost a premonition of what’s going to happen their path could come in terms of his age. And I think it scares him a little bit.”

Hal’s physical limitations in season 2 also disrupt his relationship with Kate. “Even if it’s a pattern you both complain about when it comes to who does what, it can be quite disturbing when that changes,” says Sewell.

Despite his own setbacks, Hal continues to advocate for Kate to become Vice President of the United States.

“They worked together in the past when he was No. 1 and she was there to support him. I think there have been times in the past where she was willing to make sacrifices he didn’t want her to make because of his belief in her potential and because he didn’t want anything about their potential relationship to hinder her progress ,” says Sewell. . “And I think there’s a difference in his belief in her and her idea of ​​herself that has led to him feeling like he has to be a little sneaky in the way he maneuvers people and events and even her. All those dark talents are deployed with a very good heart behind them.”

Sewell admits he doesn’t know where life will take the Wylers, but he has started filming season 3 of The diplomat in New York City. “We don’t know how long this will last,” he says. “But you thought the ending of season 1 was a shock? Just wait until the end of season 2! I can’t wait for the audience’s reaction.”

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The diplomat season 2 is now streaming on Netflix.