Penny (Kaley Cuoco) and Leonard (Johnny Galecki) will seek therapy in order to help their new marriage and find a way to live with Sheldon (Jim Parsons) in Thursday's all-new episode of "The Big Bang Theory."

"Malcolm in the Middle" alum Jane Kaczmarek will guest star as a therapist who offers support for both Leonard and Penny in Episode 12, titled "The Sales Call Sublimation."

"We have this man-child living with us named Sheldon," Penny gripes to the therapist in a preview video.

"Leonard talked a lot about him. I wasn't sure if he was real," Kaczmarek's character replies.

In response, a frustrated Penny quips that Sheldon is "as real as the fine I get when I use too much toilet paper."

The synopsis for the upcoming episode also reveals that Stuart (Kevin Sussman) will move out.

"Penny gets more than she bargained for when Leonard agrees to meet with a psychiatrist (Jane Kaczmarek) on her behalf. Also, Sheldon and Koothrappali collaborate on an astronomical discovery, and Wolowitz and Bernadette can't believe what they are feeling after Stuart moves out," the description reads, according to CarterMatt.

Meanwhile, even though Sheldon and Amy (Mayim Bialik) finally consummated their relationship in the midseason finale last month, executive producer Steve Molaro recently revealed that there is a possibility that Amy will get back with her ex-boyfriend. The showrunner made it clear that he would love to have actor Stephen Merchant reprise his role as Amy's ex later on in the season.

"He's a busy guy, but the door is wide open for him to come back," Molaro told TVLine. "We were honored to have him."

Molaro also told TVLine that the show will not continue to focus on Sheldon and Amy's sexual encounter, and will instead "move on" to focus on other characters.

"I think we will move on until the next time we talk about it," Molaro said. "Sheldon in that moment has a very clear plan in mind at the end of the episode. It's a chance for us to take a little breather from the weightiness of the Sheldon-Amy relationship and put the spotlight on some of the other amazing relationships and characters that we have on our show."

Season 9 Episode 12, "The Sales Call Sublimation," will premiere Thursday, Jan. 7 at 8 p.m. ET on CBS.

Watch a preview video below.