The Big Bang Theory: The Maternal Combustion

CBS has released new preview clips for tonight's episode of The Big Bang Theory, "The Maternal Combustion."

In the episode, Sheldon and Leonard's mothers finally meet. And while the two geeks share plenty in common, their moms couldn't be any more different. Meanwhile, Howard pitches in on the housework, albeit, with help of his friends.

You can check out the four preview videos below.

The Maternal Combustion airs tonight at 8:00 p.m. on CBS.