'The Big Bang Theory' season 10 episode 13 spoilers: Leonard and Penny deal with marital issues; Sheldon plays peacemaker by creating a relationship agreement

Sheldon (Jim Parsons) plays the unlikely peacemaker on the upcoming episode of "The Big Bang Theory" season 10.

Titled "The Romance Recalibration," this week's episode will see Penny (Kaley Cuoco) and Leonard (Johnny Galecki) hit a minor bump in their relationship. According to the official synopsis, Penny begins to feel that Leonard is taking her for granted and that he is not giving her the affection she needs.

As a result, she decides to go out with Amy (Mayim Bialik) and have a relaxing spa weekend. Meanwhile, Howard (Simon Helberg) discovers a squeaky floorboard in the baby's room, so he asks help from Raj (Kunal Nayyar) to do some house repairs.

CBS recently released a new promo for tomorrow's episode, and it shows Sheldon, Amy, Leonard, and Penny talking about their relationships. It is revealed that Penny and Leonard's marriage is in trouble, so the couple seeks advice from Sheldon. "Please help us make a relationship agreement," Leonard tells Sheldon, who appears to be surprised by his friend's request. Sheldon immediately agrees, and he seems excited to play peacemaker for the couple.

"The Big Bang Theory" is already halfway through its 10th season, and although the sitcom continues to perform well in terms of ratings, CBS still has yet to greenlight a season 11 renewal. Despite rumors of an impending cancellation, CBS Entertainment president Glenn Geller feels positive about a renewal for the show soon.

"[Contract talks] are continuing. It is tough but kind of normal negotiations," the exec said during the Television Critics Association winter press tour. "We are guardedly optimistic about it. It's normal negotiations," he added.

Insiders claim that the major cast members are all seeking salary raises from their contracts two years ago when the program scored a three-season renewal. Last year, Geller said he was "confident" about a new deal for the cast, but to date, it still hasn't been secured.

The 10th season of "The Big Bang Theory" airs every Thursday night at 8 p.m. ET on CBS.