'Big Bang Theory' season 9 cast news & spoilers: Kaley Cuoco, Ryan Sweeting split after 21-month marriage

Despite Kaley Cuoco's character, Penny, getting married to longtime beau, Leonard, in the new season of "The Big Bang Theory," the actress' own marriage to Ryan Sweeting fell apart.

Kaley Cuoco-Sweeting, 29, announced Friday that she was separating from husband, Ryan Sweeting, 28, just after 21 months of marriage. The actress told People about the end of their marriage through her rep.

"Kaley Cuoco and Ryan Sweeting have mutually decided to end their marriage," said Cuoco's rep. "They ask for privacy at this time. No further statement will be issued regarding this matter."

According to the magazine, the split was "mutual" and just after the announcement; Cuoco took to Instagram to introduce her new horse Zaza. In the photo, it could be seen that the actress has taken off her wedding ring.

According to a source cited by the Daily Mail, the reason why the couple has split was because they've come to the end of their "honeymoon phase" and they were "miserable" together.

"The few times Kaley and Ryan were out together recently, the tension was noticeable... You could tell the honeymoon phase had ended," the source said according to the outlet. "It seemed they were trying to work out their marriage by going on dates, but they both seemed miserable."

Furthermore, the site added that the two have deleted photos of one another in their respective social media accounts.

In other news, the second episode of season 9 of "The Big Bang Theory" on Monday, Cuoco's newly-wed character Penny and Leonard (played by Johnny Galecki) have worked out the issue of the "kiss" given by Leonard to his co-worker Mandy (played by Melissa Tang) at the North Sea. According to the International Business Times, episode 2 is entitled "The Separation Oscillation" and the official synopsis reads:

"Leonard confronts the woman he kissed on the North Sea in an attempt to set Penny's mind at ease. Also, Sheldon films a special episode of "Fun with Flags" after his breakup with Amy, and Bernadette feels guilty about withholding a secret from Penny."

With the marital issues solved for now, the second episode will focus on Sheldon (played by Jim Parsons) and Amy (played by Mayim Bialik) with the latter asking for space after their breakup.

According to Entertainment Weekly, episode 2 will be centered on the show that Amy and Sheldon produce and create together called "Fun With Flags." Since their breakup, Amy will no longer be in the show but Sheldon is bothered about it. To retaliate, Sheldon creates a show episode about flags from countries that have fallen because of women who were involved in its downfall. Amy confronts Sheldon about the episode and demands the video to be taken down.