Can anyone help me with a question re adult male depression/bipolar?

You don;t really describe mania or hypomanic periods which MUST be present for it to be Bipolar. Borderline PD is a possibility, so is recurring depression. When he is in a better mood approach him with the things he does (rather than say I think you have Bipolar or whatever) and tell him that he needs to get some help because it is affecting your relationship.