I appreciate this is more a legal question but find there is always more experience/traffic through here 
With DP 2yrs and currently discussing living together. I have DS6 who lives with me, he has DS18 who lives with him (though headed off to college), DS10 and DD14 who live with their Mum (not local to us). Having looked at all options it's likely that my current home is probable long term option for us.
As things stand just now everything I have would go to DS when I pop off. And while I want this to remain sane currently I think that longer term I will want to make provision for DP to ensure that he isn't made homeless...
Any thoughts, ideas on best approach?!