My bf spending Christmas day with ex and her family?

I'm sure the answers to this question range from one end of the spectrum to the other. Some people think it's disrespectful to the new bf/gf and hinders their ability to bond with the family and others think it's perfectly normal to maintain those ex relationships. Regardless of the way you or they feel about it you should be invited along because you are his partner, just another layer to the blended family. If you are not welcome then I would question ex's motives.