I realize that my siblings are not sterling scholars. We do foster care, and that means that some of our family will not act as "normally" as you would like. However, blaming my siblings for your children's porn addiction is ridiculous. I am willing to go over to your house, even though your young children are invariably the ones who you say have an issue. I will introduce my husband to them, I accept them, even though they have displeased you. Telling your son that he cannot come over to our house for family parties because my YOUNG siblings are there is attempting to fix the behavior that we had nothing to do with by adding just a touch of discrimination against foster children.
You say that you are just trying to protect your children. Doing your best to shelter them from anyone who might have introduced them to porn. I know that this is within your rights, as their parent. You might actually even think that my siblings ARE the culprits of your children's addiction. I would suggest paying closer attention to your children.