The big bang theory
Cast of Hit CBS show The Big Bang TheoryFacebook/CBS

In The Big Bang Theory Season 7, fans were delighted to see Sheldon and Amy kiss, but showrunner Steve Molaro asked viewers not to expect the couple to go "physical" just as yet.

"We're always moving them forward in baby steps," shared Steve Molaro, who added that there is no "set plan in place" for the pair to take their slow-burn romance to the next level.

"They're on the same trajectory that they've been on since they met, and that is she is continuing to drag him along into this relationship, whether he wants to admit that he likes it or not."

Big bang theory season 8
Sheldon and Amy kiss in The Big Bang Theory Season 7Facebook/CW

He continued, "He has come a long way. She's got him to a place where they hold hands and they kiss and they go on regular dates. While it may not seem like a lot, it's a colossal amount for him," reported TVline.

According to reports, Season 8 picks up 45 days into Sheldon's head-clearing, cross-country train excursion, and things will not go very well for him.

"His belongings have been stolen and he needs Leonard to come pick him up in Arizona," said Molaro.

Sheldon's girlfriend Amy is not too happy about his impromptu train trip.

Molaro told TVline, "Amy's not pissed at him for leaving, but she's certainly not thrilled that when he ran into trouble he called Leonard instead of her."

As previously announced, this season Penny will put her acting career on hold to work as a pharmaceutical sales representative at Bernadette's company. Also, her new job will create problems between her and Leonard.

The big bang theory
Penny will get a job in season 8, which will create trouble between Leonard and her.Facebook/CW

"It alters their dynamic because now she's actually doing well financially. It's a new chapter for her," said Molaro.

Howard will struggle to accept the fact that Stuart has now become Mrs Wolowitz's permanent caretaker, and Raj's relationship with his new girlfriend Emily (Laura Spencer) will be explored this season.

"We're going to explore more of her personality, and what she's really like," he teased.

Molaro quashed all rumours of having a baby Wolowitz in the show.

A Howard-Bernadette baby will not "be happening anytime soon," maintained Molaro. "We're not in any rush to have a baby on the show.

The Big Bang Theory Season 8 premieres on September 22, with an hour long episode.