Obsessed with SPN

Lily and Georgie are supernatural fangirls. Okay more then that.
They are obsessed with supernatural, they practically know every character inside out.
One day they go out in town like normal and when they see lights flicker they make references. However Dean, Sam and Cas all see and hear them and decide to question how they know this.
What will happen?
How are Sam, Dean and Cas real?
Is it a dream?