I bet it is very hard on him today, especially being his twin sister.
There is a connection there that is like no other, I have been told. Twins have a special bond unlike regular brother/sister from what I understand.
I don’t know how I would feel if my brother passed away. I know it will happen one day and I will be very sad if he goes first. He is my older brother , I couldn’t imagine the pain a twin is feeling.
I hope and pray God keeps a touch on him today and forever….but especially today.
Tell him she was blessed to live a long life and that YOU are blessed that he's still here for you to continue to love and enjoy time with. Maybe that will help him realize he's wanted and loved by his family. It might help.