1. 1. In a blender, combine seedless grapes and pineapple chunks. Blend until smooth.

2. 2. Strain the mixture to remove any pulp and seeds, leaving a smooth juice.

3. 3. Fill a glass with ice cubes.

4. 4. Pour gin over the ice in the glass.

5. 5. Top it off with the blended grape-pineapple juice.

6. 6. Stir gently to mix the flavors.

7. 7. Garnish with a slice of pineapple or grape on the rim of the glass.

8. 8. Serve and enjoy!