It’s really easy to sit and view a situation and say ‘ that’s great’ or ‘that’s terrible’. But until we have been in that situation nobody knows how any of us will react. Grief is a very personal thing and everybody has to grieve in their own way.
Some people cannot bear to be alone. Some people move on really quickly. Some people spend the rest of their lives mourning the person they have lost. Who among us is qualified to say what is right and what is wrong considering every one of us is different? Nobody is.
Maybe this man couldn’t bear any reminder of what he had lost. I don’t know the details of your sisters death but maybe he had said goodbye to her emotionally long ago. Maybe he was so happy with your sister that he just wants the same with somebody else.
Would you prefer that he spends the rest of his life in black mourning somebody who he can’t bring back and wasting his own life in the process?
How he chooses to live his life is his decision, ultimately he is the one who has to live with his conscience and if he sleeps well at night then all the best to him. If he truly loved your sister and she died knowing he adored her then he has done right by her.
I have always thought it’s odd at funerals that is always the widow/widower who is the chief mourner with the most attention ( for want of a better word). A husband of wife, while it is an horrific loss can be replaced by re marriage. In your case you can’t get a new sister. Your poor mother can’t replace her child. And I think - as your case shows- the family of a person ( more often than not ) mourn their mother/ sister/ daughter for much longer than a husband or wife. It’s just a fact of life.
Take comfort from the fact that he was obviously so happy with your sister that he just couldn’t bear to be alone.
You can’t control his grief and respecting her memory but you can control yours. So you remember her as you choose to and give your sisters son as much love and support as the poor lad needs.
As for the relationship between him and your nephew well that’s a totally different matter but I think he has behaved in a very selfish manner ( like men do) and is a total and utter shit for not putting that boys feelings above his own. But I do think that lots of men are very adept at compartmentalising their feelings and emotions and they can just move on very quickly. We really are two very different species.
Im so sorry you lost your sister but don’t let this overtake and be one the thing you think of when you think of her. Let her rest in peace surrounded by the love of her family. I read something written by a mother once and I think this applies to you and your mum.
She said ( about her daughter) “ I loved you from the moment you took your first breath, I was there when you took your last and my love for you will never change until I take my last breath and we are reunited for always”