Pinky promise/ Long distance love story

Growing up in a small farming town you hear things. From old timey legends meant to scare you into staying in your bed at night like the boogie man or tales meant to warn you about staying out past midnight.
But for our small old town we didn't have those stories, our story was about a girl who broke a promise. Not any old promise, a pinky promise.
The story goes one day a girl had promised her lover that she would always love him, they interlocked their fingers and went on with they're life. A year or so goes by and the lover finds his dutiful wife in bed with some other man. He is enraged and he cuts off her finger.
Our parents would use this urban legend to make sure we were honest and kept our word. Obviously as I grew older I would realize that the story had not really truth to it, like Santa or the Easter bunny. Except my faith in a pinky promise held up, and up until today my pinky promise had never failed me.