this girl told me "I will kill you and your child if you ever did this to me"

T
Do I have every right to be mad? So I hid my boyfriends vape in the bathroom and it took maybe 5 min to find it. I told him where it was, we were both having a good time and he wasn't even upset with it. This girl messaged me saying that. How do you feel if someone said that to you? Was this a appropriate?