More straight couples are calling each other partner. Here’s why

I'm an old guy. Since we (my "partner and I) are not married but have lived together for years (no common law here,) husband/wife doesn't apply. I don't know any other word to use other than partner, but it is still difficult for me to naturally say. Not sure why. Funnier (at our age) would be boyfriend and girlfriend. Uh ... no.