What to expect when I tell my adoptive parents

I have contacted both of my b-parents. But, I have not told my a-mom. (My a-dad is deceased.) My a-mom would have major difficulties with my contacting my b-family. Those are her issues, not mine, and I don't want to burden myself with her issues. Reunions are difficult enough to navigate. You are under no obligation to tell your a-parents about your b-parents. You can hold off on that until you're ready to disclose it. It's entirely your choice.