I don't get it -- every time I squash a bug on my windshield, I pull off the road and give it a proper burial. Funnily enough, no one goes on road trips with me anymore. Maybe your son hated his cousin?

I have a LOT of cousins, a few died over the years, many I meet maybe once or twice but had not developed any kind of relationship to forget an emotional attachment. People die, it is tragic but unless there was some kind of relationship your not mentioning beyond "family" then being interrupted just to be told someone died could easily be an annoyance over anything else.

(1) Just because it was your son’s cousin doesn’t mean they were necessarily close. (2) Not everyone processes loss the same way. Sometimes the loss doesn’t sink in emotionally for a while. Depending on the age he may not comprehend finality in the same way you do. (3) Your son may have trouble expressing or feeling emotions. If this is the case, you should have seen other clues before this. In this case you and him need professional guidance and help.

Were they close? If they weren’t, it makes total sense why he wouldn’t react much. Just because someone is blood related does not make them family. He could also be processing the news differently than you, as well. A lot of people don’t just automatically break down with bad news, it may take time to sink in before it hits them.

I had to stop myself laughing when I heard my great-grandmas died. Grief does weird brain error stuff. Let him be and he'll sort it out when he's ready. (And yes, I still do miss both of them. They were lovely ladies.)