"The Big Bang Theory" season 9 will finally see Penny and Leonard finally tie the knot, which will definitely delight the fans of the couple. However, showrunner Steven Molaro revealed that the two will be tested right away by someone from the past.

Penny and Leonard have been engaged since season 7 and the time has finally come for the two to walk down the aisle. This is major news for the fans of the show because the last season's finale saw the two run off to Vegas to get married. Fans wondered for months if the two will really settle down and just recently, "The Big Bang Theory" showrunner Steven Molaro confirmed the couple's wedding.

In an interview with TVLine, Molaro said, "We're nine years in and we want to keep things moving forward, as well as exciting and scary and fun."

He added, "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, someone from Leonard's past will throw a curve ball to the newlyweds, which clearly proves that there is so much to look forward to in the relationship of the two this coming season 9.   

Melissa Tang has been included for the new season of the CBS sitcom to play the role of the woman whom Johnny Galecki's Leonard kissed while he's on the North Sea expedition, Cheat Sheet reported. Leonard confessed this to Kaley Cuoco's Penny during season 8's ultimate episode, which only added to the question whether Penny can forgive Leonard and marry him.

Other reports about the hit series state the inclusion of the upcoming sequel to the "Star Wars" movie franchise, "The Force Awakens." According to the Christian Post, Molaro and the writers already have some "really cool ideas" as to how they will include the Episode 7 in one of their episodes.  

Clearly, there is so many things to watch out for in when "The Big Bang Theory" returns for their ninth season. Penny and Leonard will immediately face challenges as a married couple when season 9 premieres this September 21 on CBS.