Some of the most unhealthy decisions we make are done in an attempt to cure lonliness. Christmas/New Years is the national holiday for codependents. We can and will rationalize just about everything ( including contacting the ex's parents to remain connected) in the name of "the holidays". Our choices usually result in begining the new year with a serious emotional hangover.
So how about just sitting with it all and feeling real good about yourself because you made the decision that you are worth more than the sum of this guy's issues.