What you will need:
A metal spoon
Take a spoon and face it sideways (towards your audience).
Hold the spoon with both hands, covering the ends of the spoon's handle.
The bottom of the spoon should touch the table.
To show that you are bending it, press down on the table.
Let the handle of the spoon fall backwards until it lies flat on the table.
While you do that, keep your hands in the position it was when you were holding the spoon.
Tada! It is an illusion which will make people think you are bending the spoon when you actually aren't!