How?

After school, Stine was eating one of my starburst lollipops from my KK.
Moana came up to Stine and said "Hey, do you have any more? I'm starving!"
And I just sat there silently while Stine shook her head.
Moana: Promise to God?
Stine: Yep. (Knowing full well that I still had lollipops but still didn't say anything ♥)
Moana: Promise on your mothers life?
Stine: Yep.
Moana: *gasp* If you say that, you're going to die tomorrow!

Now...how the hell is SHE going to die tomorrow if she promised on her mother's life?
Confusing...

BYEBYE ♥
P.S. I have to write about KK but...I have an assignment to do. Wish me luck!