Elon Musk was reportedly involved in a romantic affair last fall with the wife of Google cofounder Sergey Brin, a long-time friend of Musk and a Tesla investor, the Wall Street Journal reported. The affair allegedly prompted Brin's divorce from Nicole Shanahan in January, WSJ reported. According to court filings, the two cited "irreconcilable differences" as the reason for the split and the filings were submitted just weeks after Brin learned of the affair, according to the Journal. A source close to the matter told the Journal that the relationship between Musk and Brin has been strained in recent months, and financial advisers instructed Brin to sell his investments in the Tesla CEO's various businesses. Brin formerly invested $500,000 in Tesla in 2008. A source told the Journal that at the time of the affair Brin and Shanahan were separated, but still living together. Read more at the link in our bio. Story by Bethany Biron. (Credit: Getty Images)