First Look: Celebrations Go Awry On The Big Bang Theory

Penny tells her family she eloped

Penny tells her family she eloped

The guys’ science skills are put to the test when they get a flat tire during Leonard's bachelor-party weekend in Mexico, and the girls force Penny to finally tell her family that she eloped with Leonard in Episode 3  ("The Bachelor Party Corrosion") of Season 9.
Penny's dad learns about his daughter's marriage

Penny's dad learns about his daughter's marriage

“The Bachelor Party Corrosion” (Season 9, Episode 3)
Penny's marriage revelation causes tension

Penny's marriage revelation causes tension

“The Bachelor Party Corrosion” (Season 9, Episode 3)
The guys plan a surprise bachelor party for Leonard

The guys plan a surprise bachelor party for Leonard

“The Bachelor Party Corrosion” (Season 9, Episode 3)
Penny spends time with Bernadette and Amy while the guys are away

Penny spends time with Bernadette and Amy while the guys are away

“The Bachelor Party Corrosion” (Season 9, Episode 3)
Amy tests out a new look with Penny and Bernadette

Amy tests out a new look with Penny and Bernadette

“The Bachelor Party Corrosion” (Season 9, Episode 3)
A flat tire derails Leonard's bachelor party

A flat tire derails Leonard's bachelor party

“The Bachelor Party Corrosion” (Season 9, Episode 3)
Sheldon, Raj, Leonard, and Howard get stranded in Mexico

Sheldon, Raj, Leonard, and Howard get stranded in Mexico

“The Bachelor Party Corrosion” (Season 9, Episode 3)
The guys try to solve their car troubles with science

The guys try to solve their car troubles with science

“The Bachelor Party Corrosion” (Season 9, Episode 3)
How many geniuses does it take to fix a flat tire?

How many geniuses does it take to fix a flat tire?

“The Bachelor Party Corrosion” (Season 9, Episode 3)
Leonard and Sheldon appear disheveled after their trip to Mexico

Leonard and Sheldon appear disheveled after their trip to Mexico

“The Bachelor Party Corrosion” (Season 9, Episode 3)