My Grandad started an affair 20 years ago, 5 years later he left my Nan and moved in with with the OW. My Nan died soon after after a fall at home alone (not relevant but info).
In the last 15 yrs he has lived as her dh, DIY etc. Her kids/ grandkids have been his with daily contact. He's worked hard, even helping her ds build his house and lots of babysitting etc. The house is plastered with photos of OW's family, there is not one photo of his kids/ grandchildren or great grandchildren. There has been minimal contact (a card at birthdays or christmas, one a yr or so phone call). He's acted like an arse generally to his family in other ways too, too many to mention.
Now he's ill with a form of dementia, caused by mini-strokes, it only gets worse if he has more. Now her family suddenly want practical/ financial help with him now he's difficult. He has worked hard for them for years in so many ways.
Are we as a family BU to say he's now their families issue? We'll lend a listening ear, be civil etc. but don't feel inclined to do much practically in terms of money for care/ letting him move in with us. Her family are well off btw, partly thanks to his input.