DH and his sister have had no contact with their father for twenty years for all sorts of reasons, needless to say they don't like him much. They were all born in Germany although DH and his sister were brought up in the UK. DH doesn't think of himself as German and has been meaning to change his nationality to British, which he can do as his mother is British.
His DS has told him that in Germany family are obliged by law to pay towards care home fees of a parent should they go into care. Their father is getting on and they've been to,d that his health is poor, his wife has very little money so there's a good chance that DH and his DS will be expected to pay. DS now also lives in Germany. if DH lives in the UK and has British nationality can the German authorities make DH pay? His DS is a sahm btw so thinks that she wouldn't have to pay has she has no earnings.