G.I. joe or G.I.jane
a person who will say anything about you even if they’re right there and can hear you talking.
My friend is a G. I. Joe. He told my crush I was a mess just because I didn't text him first.
My neighbor is a G. I. Jane. She told my dog I was a bad pet to my mom just because I forgot to feed him.
My brother is a G. I. Joe. He told my crush I was a joke just because he was mad I didn’t text him.