236 The Big Bang Theory The Bachelor Party Corrosion 09 03 2015-10-05 Comedy / Romance Jim Parsons - Sheldon Cooper / Johnny Galecki - Leonard Hofstadter / Kaley Cuoco - Penny / Kunal Nayyar - Rajesh Koothrappali / Simon Helberg - Howard Wolowitz / Melissa Rauch - Bernadette Rostenkowski / Mayim Bialik - Amy Farrah Fowler / Laura Spencer - Emily Sweeney / Sara Gilbert - Leslie Winkle / Kevin Sussman - Stuart Bloom / John Ross Bowie - Barry Kripke / Carol Ann Susi - Debbie Wolowitz The guys’ science skills are put to the test when they get a flat tire during Leonard’s bachelor party weekend in Mexico. Also, the girls force Penny to finally tell her family that she eloped with Leonard.