Article continues below advertisementKeith Urban's behavior following his split from Nicole Kidman is being described by insiders as a "pathetic mid-life crisis", with sources telling OK! his actions in recent months played a central role in the breakdown of their 19-year marriage.The 58-year-old country singer and Kidman, also 58, were once seen as one of Hollywood's most stable couples, but their relationship reportedly unraveled in September when Urban told the Oscar-winning actress he wanted out.