Future daughter-in-law is wedding stuff with my son's stepmother and not with me. Isn't that disrespectful?

FDIL has not asked me to do one blessed thing for my son's upcoming wedding. Every time I offer, I am turned down with a flat and harsh "no", sometimes before I can even get my suggestion out of my mouth. But now I hear that my son's stepmother has been asked to do a reading at the wedding, was invited to a party where envelopes were stuffed with invites and she was also invited to the bridesmaid party. I was not invited to or told about these events. Am I out of line to be hurt and to think that I am being disrespected? I feel as if my FDIL is recognizing my son's stepmother as his mother. Don't I take precedence over my ex's wife? I told my son how I felt and he said it was no big deal that his stepmom and FDIL just really hit it off. I am still bothered by it though. and before anyone asks, the divorce between me and my ex was amicable.