The Big Bang Theory's Season 10 premiere was a guest star-studded affair, with lots of people showing up for Leonard (Johnny Galecki) and Penny's (Kaley Cuoco) wedding. There were appearances by Judd Hirsch and Laurie Metcalf as Leonard's dad and Sheldon's mom -- who didn't hook up, it turns out, an anticlimactic resolution to the Season 9 cliff-hanger -- as well as Breaking Bad's Dean Norris as an intimidating Air Force officer who's inquiring about Howard (Simon Helberg) and Raj's (Kunal Nayyar) invention and 30 Rock's Jack McBrayer as Penny's ex-con brother Randall.

But one guest star stood out above all the rest, and that was Katey Sagal as Penny's mother, Susan. Katey Sagal, a national treasure for her roles on Married...With Children, Futurama and Sons of Anarchy, made the most of her small appearance, having funny interactions with Randall and her husband Wyatt (Keith Carradine).

The most notable part, though, was that it was a mother/daughter reunion for Katey Sagal and Kaley Cuoco. Sagal played Cuoco's mother on 8 Simple Rules from 2002 to 2005. That show was Cuoco's first big job before The Big Bang Theory made her a household name, so it was sweet to see them onscreen together again.

Fans were into it:

Hopefully we see a lot more of Penny's family in the future. Just one episode wasn't enough!

The Big Bang Theory airs Mondays at 8/7c on CBS.

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