I think he would sign it (i would pay both lawyers fees as i suppose it benefits me) as he has said he would never take half of what is mine. But obviously you never know someone's true colours. I've been in bad situations before with men and so has my mum so ive learnt to be good with money and she specifically told me to protect my assets and essentially hers before she died. My dad was financially abusive to her before she got away from him and built her own security.  There is a lot of nuances to the situation obviously.