Dealt with this about two years ago when my best friend and his wife split up. Previously, they came and stayed with us about a weekend a month, and we'd go on a week-long vacation together about once a year.
They had started dating at 17 and at 30 wanted different things in life. He wanted to pursue a career in video games (he had been getting calls from head-hunters). She wanted to live no further than 5 miles from her parents and wanted to be falling-down drunk every night.
They actually told me about their intention to divorce a year earlier. I convinced them to try counseling, which they did for a short while before the wife gave up and went back to the bottle. When it came down to a decision between his dream job in California and staying around for his alcoholic, codependent-on-her-enabling-parents wife, he chose to leave. I think because we knew about her problems, she was too ashamed to try to remain friends with us. The first hint we got that papers had been filed was when she un-friended my wife and I on Facebook.
So now, our friends we used to spend a weekend with a month are gone. She won't speak to us, he lives in California.
