When Mum died, for quite a long time my Dad would cry when he was talking about her. He missed her terribly.
After struggling on bravely for a while, on the 24th of September he passed away at home.
At the time of his death, he was recovering from a broken hip, he couldn't see very much, he couldn't breath without regular help from a machine, he had various inflammations and was feeling very lonely.
On balance, it's fair to say that he felt that it was time to go...perhaps to meet up with Mum. I hope so.
Go well Dad.