Is it normal for people to do this to you?

I have members in my family who say they are going to die everyday(Even when nothing is wrong with them). I also have certien friends who are generally very nice yet when I tell them about something I care about like pet or family they tell me "Oh going to be sad when they die right"? They are all going to die one day and you are going to lose them forever"! Why do people fuck with me like this? Is it normal. I have frequent nightmares of people and things I care about dying but I think this is partly the issue.