"Big Bang Theory" returns to CBS in the fall with Katey Sagal as a new guest to play Penny's (Kaley Cuoco) mom.

The star posted an Instagram photo with her new TV mom stating, "Yes yes yes yes!!! Once my tv mom, always my tv mom. Love you."

Sagal, best known for her role in “Sons of Anarchy,” played Cuoco’s mom in the ABC comedy “8 Simple Rules” that aired from 2002 to 2005.

BBT’s Executive producer Steven Molaro announced Sagal’s role in the series at Comic-Con in San Diego on Friday. He says she volunteered to play Penny’s mom Susan.

"She's going to be a little bit of a neurotic character because she's spent her life with her troubled son who has been in and out of jail and has had some issues with dealing drugs,” Molaro tells Entertainment Tonight.

The gang is getting together with their families at the start of Season 10 for Penny and Leonard’s (Johnny Galecki) wedding ceremony. They have been married for a year, but after eloping to Las Vegas, they are renewing their vows in front of their family and friends as promised.

And of course, the bride’s family members are coming into town.

Penny’s meth dealing brother Randall (Jack McBrayer from “30 Rock”) is also coming to the ceremony. We will finally get to see him after hearing many references from Penny about his time in the slammer for being “sort of a Chemist” like her beloved husband.

In the last episode of Season 9 we met Leonard’s dad Dr. Alfred Hofstader (Judd Hirsch), and reconnected with his mom Beverly (Christine Branski). Sheldon Cooper (Jim Parsons) also invited his mom Mary (Laura Elizabeth Metcalf).

Judging by last season’s finale, Sheldon and Leonard might become step brothers after speculation that their parents hooked up. Leonard’s dad and mom are divorced so it is not 100 percent bad that his dad might end up with his best friend’s mom.

Meanwhile, Howard Wolowitz (Simon Helberg) and Bernadette Rostenkowski (Melissa Raunch) are expecting a baby.

Will we get to see the little guy, or little girl? And how will that effect Howard's somewhat too attached relationship with best friend Rajesh Koothrappali (Kunal Nayya)?

Also, now that Sheldon and Amy Farrah Fowler (Mayim Bialik) are back together, will they take their relationship to the next level? Maybe they will get engaged. Or they just might have sex another time, since Sheldon promised to sleep with her at least once a year.

"Big Bang Theory" returns to CBS Monday Sept. 19 at 8 p.m. EST.

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