I am bipolar. I'm willing to give my thoughts on this.
I don't know your situation so I can only speak generally so bare with me.
First off, was he manic during the A?
Promiscuity of various types is pretty common during bipolar mania. It is a symptom, not necessarily a thought out choice.
I know no one wants to hear this but until you've had your life literally smashed into pieces and you cannot even remember how it happened...it's best not to go there.
Depending on the mania factor, he may be so ashamed of his behavior that he is desperately wishing it would go away.
I mean, we all know that many remorseful spouses feel that way, BP or not but for a BP who acted completely unlike themselves during a manic episode? It is severely unhinging.
I have periods from my first major episode that are so ridiculous, out of character and embarrassing, I can't talk about them...even with people who I know know because they witnessed it.
I won't go too far there as I don't have enough details but the shame associated with various issues with BP is some of the reason a large percentage end up killing themselves.
The cycle you mention in your last post sounds a bit like rapid cycling...up down up down fairly quickly...mood all over the place? Only you will know but if he hasn't already, it might do him a world of good to talk to a psychiatric ARNP.
It is hard...many wayward behaviors are present but you can't tell if that's what you are seeing or is it manic irritability or what.
I'm sorry you find yourself in this mess but having some talks with an MC who understands bipolar might be helpful.
I know a lot of people don't recommend MC early on and usually, I agree BUT when you are dealing with mental illness, it's a different ball game and whether you stay or go, being able to sort it out with someone who really understands can be extremely helpful.
Me: 44 BS
Him: 40 FWS
Ow: 47 head case, no obs
5 DD's: 23, 20, 19, 17, 12
Last D-day: August 2012 with lots of very blurry lines.