You should buy him a book or find a good description of it and make him read about it. You could even get him to come on here and read some of our posts, it should enlighten him greatly as to how moods can change and its not like we are wanting those things to happen.

On the other hand, I have to say that you really should consider going to a psychiatrist and getting back on meds. Also, if you aren't in therapy, you may consider that as well. Obviously, getting on meds and seeing a therapist isn't going to make the bipolar go away, but it will help and it may help him to see you are trying to get control of things.

Good luck.