You know, it sucks that someone opened your gadget when you were looking forward to opening it yourself and I could understand why someone could get upset at the situation. But there is definitely no need to go off on your own sister and mom like that.
You could have explained your point of view in an adult manner and moved on.
You probably hurt the feelings of those who love you and I hope that once you calm down you go back and apologize. You never know what's going to happen tomorrow, don't ever put yourself in a situation where you will regret your actions.
Agreed. This is a very mature way of handling it.
1st world problems... gotta love em'