DS, 7, was born in the USA, and returned to the UK with me 5.5 years ago when his father and I separated. We have not yet divorced. My ex pays no child support and has made minimal effort to maintain contact with his son: phonecalls maybe two or three times a year. No calls at all so far in 2011, not even on DS's birthday. My inlaws fly DS out to visit every summer, and took him up to visit his father three years in a row, before deciding last year that it was pointless. So DS hasn't seen his father since 2009.
What would happen if I got hit by a bus tomorrow? Would custody of DS be automatically granted to his biological father - even though he's effectively a stranger? Would DS be made to move to the US? DS and I have lived with my DP for 4 years. Ideally, I'd like my son to stay with him - the man who is his father in every emotional, financial and practical way. Would simply getting divorced resolve the problem? Would DP have to adopt DS to gain parental rights?
Thank you in advance for any advice.