Billy Joel and Katie Lee Joel have split.

"After nearly five years of marriage Billy Joel & Katie Lee Joel have decided to separate," a rep for the couple tells "This decision is a result of much thoughtful consideration. Billy & Katie remain caring friends with admiration and respect for each other."

See other newly single stars

Rumors of a rocky marriage have been surfacing lately.

See the ugliest celeb splits of all time

New York's Daily News reports that Lee, 27, was spotted dirty dancing with 36-year-old Israeli-born fashion designer Yigal Azrouel, who has frequently escorted her to events. The paper reports he has even referred to her as his "girlfriend." But a source tells Us affair rumors "had nothing to do" with the split.

See Hollywood's most expensive divorces

"Everything is very amicable and it was just a growing apart," the source adds.

Look back on the biggest splits from last year

Joel was 55 years old when he wed Katie Lee, then 23, at his 15-acre waterfront Center Island estate in Long Island, N.Y., in 2004. Joel was previously wed to Christie Brinkley (1985-94) and business manager Elizabeth Weber (1973-82).