WARNING: Major spoilers ahead

The cat is out of the bag! Apparently, Penny (Kaley Cuoco-Sweeting) and Leonard (Johnny Galecki) will officially say "I do" in the Season 9 premiere of "The Big Bang Theory."

Before Season 8 ended, Penny and Leonard agreed to elope in Las Vegas. However, Leonard began having second thoughts about eloping while they were driving to the City of Sin and he confessed to Penny that he had kissed another woman when he was drunk 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.

During a recent interview with TVLine, showrunner Steve Molaro confirmed that the couple will tie the knot when the new season debuts.

"We're nine years in and we want to keep things moving forward, as well as exciting and scary and fun," he says. "And I think this a great way to do it. Penny has had commitment issues for years and years now, especially when it comes to Leonard, and even she feels, 'How much longer are we going to go back and forth on this? Let's just jump in and hope for the best.'"

However, he warned that "that's really only the beginning of the story. As fun and as great as it is to see them get married, that's only part of it."

This could be a hint that the newlyweds will experience trouble when Leonard's new wife comes face-to-face with his "other woman." According to TVLine, "Mom" star Melissa Tang has been cast as Mandy, the woman Leonard kissed on that North Sea expedition. As a result, this could put a damper on Leonard and Penny's potential honeymoon.

Molaro also teased that the geeky gang will go on a road trip in the upcoming season.

"There will be a fun road trip to Mexico for the guys early on," the EP told Entertainment Weekly. "The road trip will be taking place in [the late theoretical physicist] Richard Feynman's van and it will actually be Richard Feynman's real-life van that we have access to -- his actual van from the '80s with the equations that he had painted on the outside of it."

Season 9 of "The Big Bang Theory" is set to premiere on CBS on Sept. 21.