With season eight of "The Big Bang Theory" ending with Leonard (Johnny Galecki) and Penny (Kaley Cuoco-Sweeting) running off to Vegas to elope, we're finally getting the first look at the wedding we've all been waiting for.

The season nine premiere will pick up in Las Vegas right where we left the two at the altar. While we know for sure that they do get married, what happens after they make it official is what's keeping fans on their toes because two years ago, Leonard kissed another women when he was overseas, and Penny is about to find this out.

"Chuck [Lorre] and I had a long talk about [revealing the wedding before the premiere]," creator Steve Molaro told The Hollywood Reporter. "That was not a positive message-and we didn't want fans to feel like, 'Oh, they're going to pull the rug again and not do it.' There is so much more story beyond that moment that we decided to just let people know."

For Leonard, it was love at first sight with Penny. After years of him trying to win her over, and the two then being in a long on-and-off again relationship, it's time for them to finally spend what could be the most awkward wedding night ever.

"I'ts season nine and Leonard has been pursuing her since three minutes of the series," Molaro said. "Even Penny, with all of her commitment issues, is in a mindset of, 'Are we moving forward with this or not? What are we doing?' And they do."

Melissa Tang will be coming onto the show in the second episode to play Mandy, who is the girl Leonard kissed on his North Sea trip. While Penny was aware that the kiss had happened, it isn't until now that she finally gets to put a name to a face. "She thinks she's OK with it and she may not be," Molaro explained. This kiss took place years before this moment in the show, it's just "a difficult thing to deal with" for Penny because she has had this certain image of the shy nerd Leonard she fell in love with for eight years now, and it's not something you expect from him. The three do attempt to talk this over so they can move on and "things will start to get better," Molaro continued. "Leonard and Penny are both invested in figuring out how to fix this."

In the sneak peek trailer for the upcoming season premiere episode "The Matrimony Momentum," which debuted on Tuesday night's premiere episode of "Late Show With Stephen Colbert," you get a glimpse of the two at the altar and even some of their vows, according to Movie Web.

Find out what really happens between the two when "The Big Bang Theory" returns on Monday, Sept. 21.

 Day 1, Season 9. Incredible. Great to be back! @normancook #ohtheglamour #TBBT #nofilter @bigbangtheory_cbs

A photo posted by Johnny Galecki (@sanctionedjohnnygalecki) on Aug 5, 2015 at 12:35pm PDT