There is documented evidence of inappropriate conduct. Pictures and emails. The legal stuff isn't anything appropriate for me myself to be involved in, as it's my loved one that's involved.

OK...well, about all I can say is that it may boil down to who has the stronger case. I have zero clue if this will make it as far as arbitration or even a judge....but a judge will be looking at facts, where there's an equitable situation....all sorts of factors. So I'd be focusing on building the strongest possible case and putting yourself in the strongest possible position.