Two and a Half Men Wiki
She dumped me.

William "Billy" Stanhope (played by Patton Oswalt) is the former best friend of Walden Schmidt who helped him create the website that would become Blungogo (Nice to Meet You, Walden Schmidt). After Walden sold the site for 1.8 billion dollars. Billy went crazy, started smoking pot and made a number of hate videos on YouTube directed at his former friend. They later became business partners again after Billy figured out the secret of the Electric Suitcase, a project the men had been working on before their split. Billy is sleeping with Bridget Schmidt, a source of tension between the men, Walden and Billy have a love and hate relationship, and even though they don't realize it, they're probably best friends. In season nine, after years of not speaking to one another, Walden and Billy start their business back up again. Walden and Billy sold their company in season ten for 1.3 billion dollars to Mark Zuckerburg. In mid season ten, Bridget breaks up with Billy, resulting in Walden, Alan, Billy, and Herb having a guy's night drinking and complaining about women.