I gave a little thought before replying to this post, and I debated whether or not I should. I figured though that I might be able to give you some idea. My mother is a narcissist, and I for many, many years was a closeted lesbian. Only in the last year or so, when I started dealing with the emotional trauma my mother inflicted on me, have I started to come out.
For other people, the answer to your question might be different, I can only answer based on my own experience. For years, my mother made me feel as though there was something wrong with me because I wasn't interested in dating or finding a man to take care of me. I had my own goals, and I struggled to hang onto those goals in the face of her abuse. I preferred to hang out with female friends when I was in high school, but instead of understand why I preferred to be with girls rather than boys, my mother convinced me it was because I was too shy, too ugly, too fat, my friends scared the boys away, too smart (boys don't like smart women), and a host of other comments about why I couldn't get a date. Never was the subject of homosexuality brought up, or the possibility of it until I went away to college, and then in an environment where I wasn't being constantly told something was wrong with me, I did start to question my sexuality. Except I was so terrified of how my parents would react that I repressed my feelings and continued to believe something was wrong with me. I ended up with a man who was just like my mother and who used me and then left me.
And after that, I constantly heard what a failure I was. How I needed to find a man to take care of me and my son? HOw I really needed to stop pining for my son's father (I wasn't). And on and on. My mother became obsessed with my sex life, making bizarre comments about my reading material, TV shows I watch, etc. Until I really felt like I had no business dating anyone because I wasn't worth it.
I don't know if it's true for all narcissists, but my mother is terribly homophobic, and even in healthy families coming out is extremely stressful. The constant fear of being discovered and having your family hate you exists for people with normal, supportive families. To come out to a narcissistic parent literally makes me sick to think about. Based on the stalking and other things my mother has done in the past, I can just imagine what lengths she would go to if she found out that I were gay. That is part of the fear that keeps me at least partly closeted. The other part is that I was raised believing that homosexuality was sinful, shameful and dirty. I grew up thinking that anything to do with my body was dirty and that same-sex relationships were the dirtiest of the bunch. That message sets up a great deal of internal homophobia that has to be overcome before any sort of real healling can be accomplished. Even though I had lots of gay or lesbian friends, when I started to realize that I was also gay, I had an extreme crisis of identity and kept asking "Why?" And then I could just imagine the reaction of my family to that, especially when my mother regularly makes homophobic comments to me.
I don't know if that answers your question. The things I've reading about homosexuality and narcissism have actually made me very depressed, and I wasn't sure if you were asking about the effect on an ACON or another narcissist.