Her big is truth

You don't exist in this world, and what's more you can't.

The reason is simple, your sister's dick is in the way.

All that exists within this dimension is the bare minimum requirements for your sister to be considered a unique entity, and then as much dickmeat as the physics system can handle without collapsing.

Every single point and wave is wrested towards the goal of being your sister's dick, and every mote complies. There is nothing else, nor could there ever be.