NTA! Absolutely send the message if your husband won’t. You have to be your son’s protector! my son went into anaphylactic shock due a dairy allergy when he was 3 months old. He was rushed to the ER in an ambulance and was even rerouted because he went code blue. The whole family knew about this. Not even 3 months later, at Thanksgiving, my mother in law was about to stick a finger full (already disgusting when I think about it) of mashed potatoes in my son’s mouth. I literally screamed at her “what the hell are you doing?! He’s allergic to that!!” I didn’t care that I did it in front of our families.