First, sexuality is not 3 little boxes: straight, bi and gay. It is a spectrum. One can be bi, and prefer mostly women, or prefer mostly men, or anywhere in between. They can also shift a little in either direction during their life but that is not real common.
This guy seems to prefer men much much more than women. I see this as a problem. He also doesn't seem to want to talk openly about his problems. This is also a problem. He needs to open up and learn to communicate BEFORE marriage.
I can admit I am a jealous person, I have borderline personality disorder which really doesn't help, so
Knowing he could be sexually attracted to both sexes, and leave me for either, rather than just females, it
just makes me worry.
Being bi does not mean he will cheat on you. You have to get to know his personality pretty well to determine that. That means he has to open up more to you. Also, I would highly recommend you get your BPD under control before getting married, if not for you, then for him. BPD can be very difficult to treat.
I have a long time interest in psychology, specializing in relationship dynamics for 30 years.
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