"The Big Bang Theory" season 9 has gone on a hiatus after airing episode 11, titled "The Opening Night Excitation", on 17 December. CBS will not be airing the next episode 12 even this week on 31 December; and is expected to return only next year. The fans can expect to catch episode 12, titled "The Sales Call Sublimation", only on 7 January, 2016.

In the previous episode, we saw how Amy and Sheldon took their relationship to the next level after 5.5 years of dating when they had their very first sexual encounter with each other. The winter finale also saw Leonard, Howard and Rajesh catching up on the new "Star Wars" movie.

Now that Amy-Sheldon have finally progressed in their relationship, the next episode will see Sheldon missing Amy, while she is away attending a neurobiology conference. While it may seem all happy and stable, showrunner Steve Molaro has hinted that Amy's ex-boyfriend will come back and that they will start focusing on other characters as well.

Though Molaro didn't clarify if Amy will dump Sheldon for her ex-boyfriend, he did tell TVline (via Latin Post) that "he's a busy guy (Amy's ex), but the door is wide open for him to come back. We were honored to have him."

"I think we will move on until the next time we talk about it. 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," Molaro said.

Meanwhile, a leaked spoiler has revealed that Penny-Leonard will be facing some marital issues and will also see a psychiatrist when the season returns for its second half. According to a report in Wikia, the newly-married couple realise that they have marital problems after they talk to Dr Sarita Gallo. Apparently, Penny visits the doctor to make a sales call, but when the doctor refuses to entertain her, Penny asks Leonard to pretend to be the client so that she can get her to buy the drugs.

But in the process, even Penny ends up having sit-ins with her and the psychiatrist tells her she has anxiety issues and that she is serving as a mother figure to Leonard and not his wife.

"The Big Bang Theory" Season 9 is on a winter break and will return with episode 12, titled "The Sales Call Sublimation", on 7 January, 2016. For more information on the upcoming episode and live streaming details, don't forget to check back here.