Leonard's Mom And Penny Become BFFs On The Big Bang Theory

When Dr. Beverly Hofstadter bonds with her daughter-in-law, it rubs Leonard the wrong way in "The Explosion Implosion."

It's nice when your spouse gets along with your parents, but what happens if they become BFFs?

Leonard ( Johnny Galecki) faces this exact dilemma in the latest episode of The Big Bang Theory, which airs on Monday, Oct. 16 at 8/7c on CBS and CBS All Access.

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It turns out that Penny ( Kaley Cuoco) and Leonard's mom, Beverly (Christine Baranski), have become super-tight, and Leonard isn't quite sure what to make of it.

Meanwhile, Howard and Sheldon bond when they drive to the desert to shoot off a model rocket.

Will Leonard stay out of his wife and his mother's budding friendship?

Or will it drive a wedge between the married couple?

Watch all-new episodes of The Big Bang Theory on Mondays at 8/7c on CBS and CBS All Access.