My eldest daughter finally broke up with her partner some 12 years ago. They had then a 2-year old daughter. He had become extremely depressed, was drinking and was sometimes violent. It came to an end when bailiffs came round to the house as he was using the property to raise money. With help of my ex-husband, he was 'bought out' of the mortgage.
For all these years he has never paid a penny towards his child, but my daughter was always determined that nothing would never come between father and daughter. She has always kept close contact with his mother and sister.
Indeed, when he became ill, it was my daughter who managed eventually to get him a flat near by.
Must admit that in those first years I just wanted him to disappear of the face of the earth, but as time has gone on, it has been so good that my g.daughter had been able to had have a good relationship with her father. She has also maintained relationship with her nanna.
He is now extremely ill, and my daughter and g.daughter visit him weekly in hospital. His Mum always asks for my daughter to be present at all meetings with medics.
Just saying that the breaking up of a relationship does not necessarily mean that g.parents do not have on-going contact with g.children.