I was about to post the very same thing. Get legal advice FIRST and then DB advice second.
From a legal standpoint, you may be best separating yourself from his childish, debt-seeking behaviors before he ruins you and you lose your house.
From a DB standpoint, it's always best to let them know that you do not want a D, and if they want one, they have to pursue it. "It's YOUR D, not my choice, so you do the work" type of attitude.
D does not have to be final, but it does make it harder. I know in my state here in the US, I can drag out D proceedings for up to 2 years - in the meantime, I'm not telling H that, so if it takes him 6 months to file, it buys me 2 1/2 years, etc.
