in fact thinking about it, being in a relationship with a man who has previously been with someone this nuts (if she is) for 16 years is a really bad call.
How did he sustain it without being bonkers himself?
I would have deep reservations...I say this as someone who got together with a man in similar circumstances, he had been in a long relationship, not married, living apart most of the time, and fraught with arguments and volatility.
He met me, decided to leave the long term partner, and after about 3 months, maybe 4, I began to realise that their relationship was still paramount and that his problems were deeper than I had ever imagined. In short it takes two, very often, if a situation is as long term as this, and there will be huge issues for him to recover from, if it was that unhappy, but he probably never will.
Mine went straight back to his ex when I finished with him, and now all I get is threatening calls from her, she sees me as a mistress, he is still heavily involved in their arguments but now I'm used as the excuse for them to argue and I get the fallout when she calls me.
I realised it was never, ever about me, and that his life was suiting him very well as it was, before I came along, however miserable he claimed to be. It was his lifestyle choice, to have that sort of volatile, crappy, destructive and violent relationship, and the freedom for a lot of affairs, which I didn't know about till she told me.
Be careful - very, very careful.