The Season 7 finale of the long-running CBS sitcom "The Big Bang Theory" is to be aired on Thursday and the show promises to end with a big bang, as well as a very close call. A number if major spoilers have been leaked about the episode and these are outlined below.

In the Season 7 finale episode, viewers will see Sheldon (Jim Parsons) considering a major move.

In the previous episode "The Gorilla Dissolution," we watched Leonard (Johnny Galecki) and Penny (Kaley Cuoco) taking the next major step in their relationship.

Penny has a terrible day at work, as she is axed from "Serial Apeist" after a quarrel with the director. Subsequently, Penny decides to undertake serious changes in her life, including her relationship with Leonard. She suggests to Leonard, "We could get married," and the latter not only agrees to the idea, but immediately takes out a ring, which he has been carrying for ages.

Although Penny is eager that the characters tie the knot, will their engagement actually culminate in marriage?

Talking to The Hollywood Reporter in Feb., Cuocu said, "I am ready for them to get married," adding, "Maybe because I just got married - so come on Penny and Leonard, it's been six years! It just took us six months! But I hope that's in the cards for them."

Many fans of "The Big Bang Theory" are also expecting that a grand wedding is on the cards for Leonard and Penny. Some fans have even tweeted to congratulate the couple on their engagement.

Nevertheless, the wedding may create a problem for Sheldon, who as usual is against any major changes that could affect his daily routine and life. Since the beginning of the show on Sept. 24, 2007, Leonard and Sheldon have been roommates, so it is very likely that Sheldon will not be pleased with the idea of Leonard leaving him to live with Penny.

The question is, will the engagement have any adverse affects on their friendship? Or will Leonard and Penny's engagement inspire Sheldon and Amy (Mayim Bialik) to take the next big step in their lives as well? Another issue still, is even though Penny has agreed to suddenly get engaged, she did suggest getting married after suffering bad news, and all of a sudden, indicating that she could cancel things later if it's not exactly what she wanted to do - she might not be ready for it.

It seems that by the end of the finale, Sheldon will go AWOL.

In an interview with TVLine, Jim Parsons said, ""He gets the hell out of there and I have no idea where he's going or what he's planning."

Parsons continued, "I won't know until I come back and read the first episode (of season eight)."

Talking about his character Seldon, the actor said, "All the (personal and professional) changes that are taking place finally start to come home to roost for him as problems."