DH and I got married a year ago. I did not include my FSIL in the wedding party because we are not close and she has never been pleasant to me. I simply didn't want a source of negative energy around me on my wedding day. A few months before the wedding, my FMIL (whom I adore) took me aside at one of my showers and, in a moment very unlike her, told me I needed to find a wedding day role for my future sister in law. Her tone and her demeanor seemed to imply that she would be very upset if I didn't include the sister, so to keep the peace, she read a passage during the ceremony.
Flash forward and my SIL is now planning her wedding. I have made a concerted effort to improve our relationship since she got engaged and expressed my support for the marriage (which is not supported by her parents). I reiterated my offer to do whatever was needed on her big day at a Christmas event and she told me to just enjoy the day as a guest. Surprisingly to me, I am a bit offended. I feel like I was held up to give her a role in my wedding and feel included and she is not showing the same courtesy to me. It is especially offensive given that I have recently put much effort into our relationship and forgiven a lot of her rather horrendous behavior toward me in the past.
My inclination is to let it go, making this more of a vent, but it still just bothers me. What would you do?