M.C.
My boys lost their grandfather two years ago and it was very hard on them. My oldest, who took it the hardest was given a bracelet of his grandfathers and was told that Grandpa wanted him to have it. I notice he wears it once on a while. I think it helps him cope.
Perhaps they are afraid of something happening to you or their father. That weighs the heavey on kids as well.
I would also ask Tony if there is something he needs to tell you or talk to you about. Maybe something else is going on with him? How are his grades in school do you see a change there? I dealt with a very angry teen at one time too but his anger stemmed from something completely different than what I thought it was. You really need to find out what's going on with him.