Pineapple Grapefruit Swirls

Directions

1. 1
   In a metal tray, stir together 1 cup of the grapefruit juice and the sugar until the sugar is dissolved; fit the tray with the divider and freeze the mixture until it is frozen solid.
2. 2
   In another metal ice tray fitted with the divider, pour 1 cup of the pineapple juice and freeze it until it is frozen solid.
3. 3
   (The fruit mixtures may be prepared up to this point 1 day in advance.) In a blender, blend the frozen grapefruit juice mixture with 1 1/2 ounces of tequila and the remaining 1/4 cup grapefruit juice, scraping down the sides occasionally, until the mixture is smooth but still frozen and divide the mixture between 2 stemmed glasses. In the cleaned blender, blend the frozen pineapple juice with the remaining 1 1/2 ounces tequila and the remaining 1/4 cup pineapple juice, scraping down the sides occasionally, until the mixture is smooth but still frozen.
4. 4
   Pour over grapefruit mixture.
5. 5
   Makes 2 drinks.