From a male perspective I was married for 20 years and never once cheated on my wife. Did I have opportunity? Yes. Did I think about it? Yes. Any man who says they have never thought about it is not telling the truth.

You say you have been married for 21 years and this is the first episode? I just find that very interesting that this would be the first episode of mania. Never heard of anyone going that long without a manic episode.

Not sure of his age but is it possible that a combination of mid life crisis and a manic episode that just made this situation much more elevated?

From my experience being bipolar alone would not put you in a situation where you did not know what you were doing.

The alcohol is a no no....a normal person drinking can make bad decisions. Someone with BP and in a manic episode drinking tend to make horrible decisions.

I wish you all the best.