After driving to Vegas to get married, Penny struggles with Leonard's confession that he kissed another girl. Also, Sheldon doesn't know how to act after Amy pushes pause on their relationship.

The guys surprise Leonard with a belated bachelor-party weekend in Mexico, but their plans hit a bump in the road when they get a flat tire on the way. Meanwhile, the girls lean on Penny to tell her unsuspecting family that she and Leonard eloped.