Hello & Welcome,
so the Drs think medication wise he is doing OK?
If so,
Sometimes parents need to make sure they are a firm united front.
I don't know if you even watched any of those Nanny shows, where the nanny comes and gives advice to the parents?
They had some good things in those- but being a team together was the main point I think.
and expecting good behavior - not letting things slide by.
He can't manipulate either of you if you don't let it happen.

This is just what came to my mind as I read your post.

I'm sure there are some good books too - but off hand I can't think of any titles.
I hope some others have some info for you
Are there classes for parents of Bipolar children - how to cope, etc?