I know this might sound outlandish, but have you considered befriending the girlfriend? Perhaps her bossiness comes from having run a household with a lousy husband of her own. As previously mentioned, she is likely unaware of your ex's previous infidelity. I know it may seem unrealistic, but befriending the girlfriend is the best way to know what is happening with your kids when they are away from you. Even if friendship never happens, getting to know each other can go a long way in helping your kids cope with this situation.
