I wonder if I'm being over sensitive about.
When I got married I didn't change my name, I discussed it with DH and agreed that I would if he would but he wouldn't so neither of us did. Both of us very happy with this arrangement. I discussed it with my in-laws, not to ask permission but just to let them know which I thought was courteous. Their response was what it is to everything "doesn't bother us."
I agreed with DH that DCs would have his name and in-laws duly informed.
Now, three years on they persist in referring to me using my husbands surname. I feel less aggrieved when they address things to both my husband and I as Mr and Mrs DHs surname. But when they send me a birthday card it is addressed to pukous DHs surname. They have never referred to me by my actual name the whole time I've been married.
Reading this back it's a bit of a first world problem but just wondered if I was being a bit U to be pissed off by this.