in laws from hell

I'm married to their son, we've been together 4 years and have a son together. They don't have any pictures of my son and I in their house, they don't have our birthdays up on their family birthday calendar, I've been apart of the family for 4 years now and they still don't take my shellfish allergy into consideration. Mean while they've got loads for pictures of their other grand babies. Why can't they just accept my son and I?