I live with my SO. As far as I can tell, she didn't completely abandoned belief in belief. She also doesn't seem to accept Occam's Razor (seemingly because it "doesn't interest" her), and use that to reject many-worlds. Or maybe many-worlds sounds absurd, and she only reject Occam's Razor by contraposition.

Anyway, all this has been a source of significant tension, which is now subsidized (I hope). The factual disagreements remains, though. Lesson learned: "Thou will not convince everyone".

As for our values, I didn't noted any significant divergence yet.