@Pineapple0502 Hey, sorry I am so late but what if you tried testing it a little? Have them watch an LGBT+ movie/ series and see how they react. Mention an LGBT+ couple in the media, or show them a video. If they react positively, start dropping more hints. For example, I started saying how hot female actresses (I'm she/her) were, as well as male actors. If that is taken well, then it should be safe to say it.
For being NB, it's probably best to go the same route. Introduce them to NB actors/ characters and gage how they react.
Hope everything goes well, you are entirely valid however they react, and you are loved!!