There's a difference between the polite use and the impolite use. If someone makes a point to always introduce and discuss their husband, some anti LGBTQ folks will make a point to never say husband. Like, "you don't get to have that word." It's a way of suggesting people aren't married.

The difficulty is that partner is also acceptable and polite, especially when gender or marital status is unknown.

It's subtle, which is exactly the sort of thing this thread is about -- ways to subtly exclude someone while appearing polite to outsiders.