Season 9 of "The Big Bang Theory" started off with a bang on Monday night as Penny and Leonard finally tied the knot while Amy officially called it quits on her relationship with Sheldon.

During the Season 8 finale, Penny and Leonard agreed to elope in Las Vegas. However, Leonard started having second thoughts and confessed to Penny that he had kissed another woman when he was drunk on a North Sea expedition two years ago. Penny assumed that he told her this in order to sabotage their plans to wed, but Leonard assured her that he's totally committed to the idea, so they agree to go through with it.

The Season 9 premiere picked up right where the finale left off and Leonard and Penny finally said "I do" in a random Chapel of Love in Vegas, reports Entertainment Weekly. However, Penny couldn't seem to move pass Leonard's infidelity on their wedding night. Leonard also made the situation worst by admitting that the woman he kissed is his current coworker, Mandy Chow, who Sheldon later described as attractive and smart. As a result, their wedding night went sour, and the newlyweds returned home to their separate apartments.

Meanwhile, Sheldon persistently tried to win Amy back and ignored her wish for space. However, this only pushed her even further away from him.

In the next episode, which is titled "The Separation Oscillation," Sheldon will use "Fun With Flags" to try to win Amy back, while Leonard will confront Mandy in order to resolve the conflict in his relationship with Penny.

"Leonard is going to confront the woman he kissed on the North Sea in an attempt to set Penny's mind at ease. Also, Sheldon will film a special episode of 'Fun with Flags' after his breakup with Amy, and Bernadette will feel guilty about withholding a secret from Penny," reads the synopsis, according to The Hollywood Hills.

In an interview with The Hollywood Reporter, executive producer Steve Molaro opened up about how Penny's father will react to Leonard as a son-in-law once he finds out that his daughter has eloped.

"We see him again in the third episode and we'll see Penny talk to him and let her father know what's going on there," Molaro teased about Penny's dad Wyatt, played by Keith Carradine. "Leonard doesn't cross paths with Penny's dad in this episode, but we'd love to have him back down the line. The vibe between Wyatt and Leonard is fantastic. The marriage is all so new to him; we don't dig too much into fatherly advice yet. You'll have to see how it all plays out.

The EP also revealed that Leonard and Penny will have some regrets about eloping.

"They come back and there's certainly some level of regret in that walk up the stairs. They're more worried that they're not sure how to fix it. I don't know if it's regret yet. They're still hopeful it can be fixed, they're just not sure how. I'm always hopeful for Leonard and Penny, without a doubt -- and for all of them. I want all seven of them in this world to be OK," he said.

Molaro went on to tease that Leonard's and Penny's interaction with Mandy will be "awkward."

"It's pretty awkward, it's not well advised that he talk to her. But he feels that he doesn't have many options left. So he's really grasping at straws. Ultimately, with or without Mandy in the picture, this will come down to Leonard and Penny and [a question of] is their relationship strong enough to get past a Ming like this or not. In the end, it will come down to them and them figuring it out on their own. But I think there's a good chance," he said.

Season 9 Episode 2, "The Separation Oscillation," will premiere on Monday, Sept. 28 on CBS.