'The Big Bang Theory' casts Katey Sagal as Penny's mom

"The Big Bang Theory" is finally introducing Penny's mom, and she's already a beloved TV matriarch. "Sons of Anarchy" and "Married with Children" alum Katey Sagal will join the hit CBS comedy as the mother of Kaley Cuoco's character in the first episode of Season 10, showrunner Steve Molaro revealed at Comic-Con. We'll also be meeting Penny's brother in the Season 10 premiere, but Molaro declined to reveal the casting for that long-awaited role.

Molaro also revealed what went into writing Sheldon and Amy's long-awaited "coitus" last season, admitting, "Not since the loss of my own virginity have I stressed out or been so invested in a single physical act. It meant a lot to us, it was a long time in the making." Molaro said that a couple of aspects of the episode were planned a few years in advance; he knew he wanted to include Bob Newhart as a Force ghost to "give Sheldon some fatherly advice," and thought that if it happened on Amy's birthday or another annual date, Sheldon could say that he looked forward to doing it again next year.

More to come...