Married Couple Ignoring Mechitzah at Home Minyan
Question
About a year and a half ago I started operating a minyan in my house on Shabbat and Yom Tov because I had to say kaddish and I am too disabled to walk to shul. At first, around 25 men were coming. A few women came too, necessitating that I put up a mechitza and create a small women’s section. I have continued this minyan even though I no longer need to recite kaddish.
My minyan has mostly shrunk as most of the original attendees lost interest, but at the same time, I have gained a few newcomers who have helped keep it alive. Among the recent newcomers is an older couple who have been lifelong conservative Jews who are accustomed to sitting together. Whenever they come, they pull two chairs to the back of the room and sit side by side behind the mechitza area.
This couple has ignored me telling them about the mechitza. I fear if I chide them for this behavior, I risk losing him from this minyan in which every male who attends matters toward its existence.
If this couple is skirting the mechitza, can I count the man toward a minyan? Can he be given an aliyah? Or should I tell them not to return, which would be detrimental to the minyan?