The Big Bang Theory Season 9 Episode 1
The Matrimonial Momentum
Penny and Leonard make it to Vegas, and Penny insists she still wants to get married. Meanwhile, back home, Sheldon is upset about what's just happened with Amy.
Sheldon calls Leonard just as they are about to get married, and tells him not to do it. Then he shares the news that Amy broke up with him.
Penny and Leonard choose a wedding package that allows their friends to stream it live on the internet. So, the gang gathers at Howard and Bernadette's to watch it happen. However, that becomes awkward when Sheldon isn't invited, but shows up to watch anyway.
Amy breaks it off with Sheldon officially after he insults her, and everyone misses the moment when Leonard and Penny are pronounced husband and wife.
Leonard and Penny get to their hotel room, and only then does Penny learn that Leonard works with the girl that he kissed.
Sheldon calls his mom to tell her to take Amy out of her mother's prayers, and to say he can send her the ring back.
Penny and Leonard arrive home upset with one another. Sheldon takes it upon himself to bring Penny a hot beverage, and they talk about their troubles.