Bill and Melinda Gates were planning the divorce for a long time: Source

Bill and Melinda Gates were planning their divorce longer than we might think.

According to sources, the husband and wife had already reached a civil agreement to end their marriage and were just waiting for their youngest daughter Phoebe to become an adult.

"It's absolutely because their youngest child is graduating from high school, and the idea was that they stayed together through that," the source says. "They limped through until their kids were out of school like a lot of people."

"Nobody is going to want to invite more scrutiny because it'll hurt their credibility," the source says. "I don't think they're so angry that anybody wants to take each other down, like you sometimes see. [Melinda is] not incentivized for that."

While the divorce was officially filed on Monday, the document says that Melinda and Bill Gates have a separation agreement in place, the one that allows private and civil end of the marriage.