Big Bang Theory
Sheldon (Jim Parsons, left), Raj (Kunal Nayyar, center left), Leonard (Johnny Galecki, center right) and Howard (Simon Helberg, right) run into trouble on their way to Mexico in episode 3 of "The Big Bang Theory' Season 9. CBS

In episode 2 of CBS' "The Big Bang Theory" Season 9, Sheldon (Jim Parsons) helped Leonard (Johnny Galecki) and Penny (Kelly Cuoco-Sweeting) set their marriage right with his suggestion that Penny simply meet the woman Leonard had kissed on his North Sea trip. Now that the newlyweds are happy, it is time to start celebrating! What will happen in episode 3, "The Bachelor Party Corrosion"?

According to the synopsis for the new episode, the boys decide that, now that Leonard is out of the dog house, he needs a bachelor party. They plan a surprise trip to Mexico where the gang of geeks plans to get wild. What could go wrong? Apparently, everything! The synopsis reveals that the group will get a flat tire on the road, while the promo shows them needing to tie Sheldon up with ropes and a blindfold just to get him in the van.

What will the girls be up to while the boys are clumsily making their way south of the border? The synopsis reveals that Amy (Mayim Bialik) and Bernadette (Melissa Rauch) will be putting the pressure on Penny to tell her parents that she and Leonard have eloped. However, she is worried that they will not approve of her Las Vegas spontaneity.

Meanwhile, Amy wants a makeover to help her get over her breakup with Sheldon and Penny and Bernadette are more than happy to give the not-exactly-fashion-forward Amy a new look. In the promo for the episode, the pair chomps at the bit to change just about every aspect of her wardrobe.

Watch the promo for episode 3 below:

Will the boys make it to Mexico? Will Penny tell her parents about her wedding? Fans will have to wait to find out. "The Big Bang Theory" airs Mondays at 8 p.m. EDT on CBS.