David Foster and Katharine McPhee – 34 Years

David Foster is a pretty big deal in the music industry. With 16 Grammy awards to his name, you can understand why. He also has a reputation in the marriage department, and his five marriages prove it. He acknowledged that his failing marriages were an issue, and did some soul searching after marriage number four.

He has been putting a lot of effort into his fifth marriage to 2006 American Idol runner-up Katherine McPhee. There’s a 34 year age gap between them, and McPhee is actually one year younger than Foster’s third daughter. They’re still going strong despite this, and in 2021 McPhee gave birth to their first child.