It is very common for ex-spouses to become mean, aggressive and disrespectful around the holidays. Call it the "Grinch" effect. Essentially, he (or she) wants to ruin your holiday because they may be jealous of your new life, angry that you initiated (or followed through with) the split, or they could simply be lonely and want to add a new resident to Miseryville. Suffice it to say, he (or she) could be like the Grinch that Stole Christmas.
Fortunately, you can be resilient just like the Whos in Whoville. The following tips can help.
Focus on happiness - Remember how the Grinch finally learned about the spirit of the holidays? After his revelation, he was warm, generous and fun to be around. The idea of seeing the children happy may spark a change and spare you any pain. It will be even better if you make it seem like their idea.
Keep a happy tone - Remember to keep an upbeat tone (especially in e-mails), no matter how demanding the Grinch may be. Fighting back or arguing only plays into his plans to ruin your holiday season.
Celebrate regardless of the pain - While it may be easier said than done, you should make your holiday special despite the pain your ex may try to inflict. Good friends and family can help you keep perspective and help you avoid missing out on special times.
Know Your Order - Above all else, know what your custody order or parenting time decree allows for in terms of holiday schedules. Most decrees allow time for both parents to have time with the children (i.e. Christmas Eve with mom, Christmas morning with dad).
Source: Examiner.com, Classic Christmas review: How the Grinch Stole Christmas, December 2, 2012