With me, going into mania, I did cheat on my spouse and made very irrational decisions too. I think they call it hyper-sexual during a manic episode. I am back on Lamictal and it seems to help me, so I wouldn't worry about that. I would try and talk to her and try to get her help; not because she would cheat, but because she would need help.

I know it is hard but it will be ok, friend.