grapefruit mojito

Oh, mojito. How I love thee.
Mojito is the #1 drink that I make, because I love all things mint.
I got a hold of a grapefruit to make some grapefruit guacamole, so I decided to make myself a drink while I was waiting to leave.

2 oz. white rum
1 oz. lime juice
1/4 grapefruit (skin removed)
1-2 tsp granulated sugar
handful of mint (go crazy! I would!)
Sprite

1. Throw mint leaves, lime juice and granulated sugar into a glass.
2. Muddle; add grapefruit and muddle lightly
3. Add rum + ice.
4. Top off with Sprite.
5. Garnish with mint leaves.

I prefer using Sprite over 7UP or sparkling water. Yes, the “right” way of making it would be to use sparkling/soda water, but my logic is: Sprite already has sugar/sweetener and lemon flavor in it already, so why must I add more sugar?