Elon Musk had a brief fling last fall with Sergey Brin’s wife, prompting the Google co-founder to file for divorce earlier this year and ending the tech billionaires’ longtime friendship , according to people familiar with the matter.
His downfall is one of a series of personal problems that Mr. Musk even as he juggles business challenges, including manufacturing disruptions at Tesla and a court fight over his desire to withdraw his $44 billion bid for Twitter Inc.