Jealousy has come between Nicole Kidman and husband Keith Urban once again! The writers of Season 2 of HBO’s Big Little Lies “have decided they want Nicole to have a hot, passionate affair with a young actor,” a source exclusively tells In Touch.

According to the insider, Keith 50 — who was “very sensitive” and “jealous” over her steamy scenes with onscreen husband Alexander Skarsgård last season — isn’t happy. The Australian-born country crooner “thought he had nothing to worry about [this season] since Alexander’s character was killed off,” says the insider. “Nicole’s potential new storyline is causing a lot of tension in their relationship.”

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Alexander and Nicole at the 69th Primetime Emmy Awards on Sept. 17. (Photo Credit: Getty Images)

Nicole’s character is going to get “involved with a charming young stud with a very dark past,” another source adds. The Oscar-winning actress, 50, isn’t doing much to help the situation. “Nicole is intent on going forward with the storyline,” the first insider says. “She wants to do what’s best for the show.”

Despite their current marital strife, Nicole took to social media on Thursday, Oct. 26, to wish her musician hubby a happy 50th birthday in a touching Facebook post. “Happy birthday to my husband, best friend, lover, baby daddy and the greatest man in the world,” the Aussie beauty wrote. “We are so lucky that you are ours. Love you from Nicole Mary, Sunday Rose & Faith Margaret xx.”

The pair tied the knot in June 2006, and share two daughters — Sunday Rose, 9, and Faith Margaret, 6 — together. Nicole is also mom to two grown children — Isabella, 24, and Connor, 22 — with her ex-husband Tom Cruise.

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