Melissa Rauch

Sheldon wants Penny to give him acting lessons, hoping that they will help him become a better teacher. Meanwhile, Koothrappali fantasizes about his best friend's girlfriend.

Raj attempts to cure his social anxiety disorder of talking to women, while Penny uses Bernadette to spy on Leonard and his girlfriend.

When Howard finally breaks the news to his mom that he's engaged to Bernadette, it lands her in the hospital.

Tension runs high when everyone is staying at the same hotel for a science event and Bernadette runs into her ex-boyfriend (guest star RICK FOX three-time NBA champion with the Los Angeles Lakers).

Priya uses her lawyer skills to pick apart the roommate agreement...and put Sheldon in his place. Meanwhile, the girls take Sheldon dancing.

Penny asks Leonard to lie to her father, Wyatt (guest star KEITH CARRADINE), while Howard, Raj and Bernadette pull an all-nighter at a telescope.