My son has favored me (his mother) since birth, which has cause a lot of hurt to my husband. Now, at 4 years-old, he has grouped our family so that he is always with mommy and his 2 year-old sister with daddy. We have tried to explain to him that mommy and sister can be a team sometimes, but it is a lot more than just "team" associations. It becomes very hurtful to daddy. Daddy used to get very upset by it, but resently has tried a different approach by talking to him about it and I try to help set a good example for our son as well. We certainly do not encourage this behavior. Advise would be appreciated. We're not sure how to further handle this.