How do I convince my family to invite my non-Jewish partner to Shabbat?

Dear Sex and the Shtetl,
One of my partners is Jewish and the other is not (we are polyamorous). My Jewish partner doesn't enjoy participating in festivals or Shabbat. My non-Jewish partner, on the other hand, is super interested in all of it. I would like to bring my non-Jewish partner to a Friday night meal with my extended family but my parents think it's inappropriate. Are they being unreasonable?
Jew-nicorn in the Shtetl

Dear Jew-nicorn in the Shtetl,

So you’ve got one partner who shares the heritage but has no interest in sharing the herring, and another who’s got all the ruach but none of the bloodline. In other words, your Jewish partner shrugs at Shabbat while your non-Jewish partner wants to lead the blessings, and your parents are clutching their chai pendants as if you’ve just invited Kanye to officiate your nephew’s bris.

Let’s pull this apart like an enthusiastic Sephardi uncle distributing challah at chag (my morsels of truth will be hard, but unlike him, I won’t throw them at your head).

You asked me if your parents are being unreasonable? My knee-jerk reaction is yes. And also, no. And also nu, it’s complicated.

I’m going to assume you’re aware that you’re living a life that challenges the default settings; not just monogamy but also the neat little categories that the majority of Jewish people use to make sense of relationships, religion, culture and whose turn it is to bring the challot.

For your parents, Shabbat dinner might still feel like a sacred space that’s governed by centuries of tradition, rituals and whatever your most intimidating cousin thinks is ‘appropriate’.