The last episode of "The Big Bang Theory" Season 8 left the future of two relationships in jeopardy - Sheldon Cooper (Jim Parsons) and Amy Farrah Fowler (Mayim Bialik) broke up, with the latter asking for space and time to think of the direction their romance is heading; while Leonard Hofstadter (Johnny Galecki) and Penny (Kaley Coco-Sweeting) decided to elope to Las Vegas.

In the official synopsis of "The Big Bang Theory" Season 9 released by CBS to TV Line, it looks like the main focus of the upcoming season will be the problems plaguing the couples. It read, "Brilliant Sheldon is confronted by a mystery of the universe he cannot unravel: when a woman wants time apart to think, exactly how much time does that mean, and is there any way to hurry the process along? In Las Vegas, Penny and Leonard march closer to marching down the aisle, but has Penny gotten over Leonard's infidelity? And if so, will he do anything to un-get her over it?"

The love story of Leonard and Penny began way back in the first season of "The Big Bang Theory," with the genius crushing hard on his waitress neighbor before she finally took notice of him. While it took quite some time for Penny to finally consider Leonard as a potential boyfriend, the two eventually got together and became one of the main couples in "The Big Bang Theory." Throughout their romance though are other flings and relationships that occurred while things were rocky or when they were on break. Despite the numerous people passing their lives, both Penny and Leonard found their way back to each other's arms and are now planning to get married.

With the wedding preparations driving them both crazy, Penny and Leonard decided to elope to Las Vegas in the finale episode of "The Big Bang Theory" Season 8. On the way to Las Vegas, Leonard dropped a major bombshell on his fiancée - that is, he kissed another girl while on a boat trip.

Questioning the reason for Leonard's sudden need to reveal his infidelity at such an inopportune time, Penny accused him of getting cold feet and not wanting to go on with their wedding. However, Leonard assures her that the only reason he chose to disclose the incident is his desire to start their married life with no secrets at all. While this appeared to have calmed Penny a bit, it remains to be seen whether or not she believes him. More importantly, it is still a mystery if Penny could overlook the infidelity of Leonard. Spoilers reveal that Penny and Leonard actually make it to a Las Vegas chapel but no word is out on whether or not they entered the church and finally went through with their plans.

As if the rocky start of their supposed walk down the aisle is not enough, TV Line also confirmed that the alleged third party in Penny and Leonard's love story will be making an appearance in "The Big Bang Theory." The actress playing the role of the "other girl," only identified as Mandy by Leonard, is Melissa Tang. Apart from "The Big Bang Theory," Tang also appeared in some episodes of "How I Met Your Mother," "Mom" and "New Girl."

Speculations are rife that Tang will not immediately appear in the first episode of "The Big Bang Theory" Season 9, titled "The Matrimony Momentum." She will be introduced by the second episode of the season instead. Given that the future of Penny and Leonard's wedding remains unknown, it should be interesting to see how Tang's character will shake things up in "The Big Bang Theory" Season 9.

As for other potential plot rumors, "The Big Bang Theory" Season 9 will reportedly also feature the back story of Amy in an effort to flesh out the character of Sheldon's girlfriend. This might include stories about her previous schools and friends - a storyline that might introduce the possibility of a new love for the brokenhearted genius.

Another spoiler plot floating around is a potential automobile accident involving the two main couples of "The Big Bang Theory" will happen in Episode 2 as well. While this seems a bit farfetched considering that a lot of unresolved issues still exist, it is not impossible. From the perspective of the writers, this accident - be it minor or major - could provide the other characters in the show to relay their stories.

"The Big Bang Theory" Season will premiere on September 21, 2015 on CBS.