Did he threaten me advice?

My girlfriends older brother hates me. No lie he is weird almost unnormal. He is always trying to do everythingtl to keep me from her. He tried to run me over and being real mean. So i went up to him and asked him why he was wearing sunglasses it nightime and he told me "why are you wearing your face its not halloween. and so i got scared and walked back to my girlfriend he comes up to me and says "if my sister drops a tear from her eye im gonna hunt u down and kill you myself". Then i asked him why he hates me and if we could work it out because i am going to date his sister. He said ."talk to me again and i will rip your ****** throat out with my teeth" i am so scared so i asked his other sister and she said hes being the pack leader and he will attack me if i provolke him. Whats that supose to mean. I talked to my girlfriend and she said the same thing her sister said not to provolke and apoligized for not warning me about him.