By the time Melinda French Gates decided to end her 27-year marriage, her husband was known globally as a software pioneer. But in some circles, Bill Gates had also developed a reputation for questionable conduct. On at least a few occasions, Mr. Gates pursued women who worked for him at Microsoft and the Bill and Melinda Gates Foundation. And then there was Jeffrey Epstein, whom Mr. Gates got to know beginning in 2011, three years after Mr. Epstein, who faced accusations of sex trafficking of girls, pleaded guilty to soliciting prostitution from a minor. Ms. French Gates had expressed discomfort with her husband spending time with the sex offender, but Mr. Gates continued doing so. So, in October 2019, when the relationship between Mr. Gates and Mr. Epstein burst into public view, Ms. French Gates was unhappy. She hired divorce lawyers, setting in motion a process that culminated this month with the announcement that their marriage was ending. Mr. Gates [and] Mr. Epstein ... spent time together on multiple occasions, flying on Mr. Epstein's private jet and attending a late-night gathering at his Manhattan townhouse. "His lifestyle is very different and kind of intriguing although it would not work for me," Mr. Gates emailed colleagues in 2011, after he first met Mr. Epstein. For years, Mr. Gates continued to go to dinners and meetings at Mr. Epstein's home, where Mr. Epstein usually surrounded himself with young and attractive women.