Literature, advice for family members coming to terms with a gay son

Hello All. I've been around for awhile but I mostly lurk. I appreciate DU and this form. This post is seeking advice about how to deal with my sister, who seems to have a difficult time with me being gay.

First, a little background. I am in my mid-twenties and have been in a stable relationship with my boyfriend for nearly three years. We have lived together for awhile in the same town as my parents. My parents and (only two years younger) sister know I am gay. My mother and sister, both religiously conservative, did not take it well, but my mom has been making an effort. My dad never seemed to have a problem, which I attribute mostly to him not having the same religious beliefs as my mother and sister. My parents have gotten together with my significant other and I several times, and have been friendly. My sister has yet to meet him and does not acknowledge him in conversation at all.

I recently spent some time visiting my sister and parents. My boyfriend was not invited and I didn’t press the issue. I did bring up him fairly frequently in conversation. My parents at least minimally included him in discussion when appropriate. My sister completely ignored his existence as if my statements containing his name had never been uttered. It came to a head when she brought up how I had to come to her graduate school graduation ceremony again without inviting or acknowledging my other half. That was the proverbial straw that broke the camel’s back. I made a point of including him in my plans to attend her graduation which she again ignored until she finally scolded me for not asking her about what I planned to do.

Due to that experience, I resolved to no longer leave who I consider my life partner out of family events. We have been together almost three years and I consider him a part of my family. I will no longer leave him behind in order to not “rock the boat” with my family. We will spend Christmas together this year; it looks like we will spend it with his immediately family, as they are much more open and accepting. My family will have to evolve and adapt.

I am not particularly close to my family, because I feel that I am so different, but I would like to make an effort to improve the relationship. Any advice? Any resources or literature you all would recommend? Thanks in advance.