Pour the vodka, grand marnier and grapefuit juice into a shaker and shake vigorously for thirty seconds. Pour the contence into a sling glass Then top up with lemonade leaving around 3 centimetres left in the glass. Float the cranberry juice over the back of a teaspoon creating a layered effect. Garnish with two wedges of lime with a grapefruit wedge in the middle. Enjoy.