Ingredients
2 oz. tequila
half of a fresh lime
half of a fresh grapefruit
2 oz of grapefruit soda (I used Izze [1] brand)
sliced lime for garnish
Directions
Combine all ingredients in a glass, add a few ice cubes, and give a stir.
Adapted from CamilleStyles [2] and Michael Ruhlman [3]