Sweet in the perfect way.
In a small saucepan, bring the sugar, water and rosemary to a boil. Remove from the heat and let stand for 2 minutes. Strain and discard rosemary. Stir in the grapefruit juice and lime juice.
Pour into a shallow 1-qt. dish; cover and freeze for 45 minutes or until edges begin to firm. Stir and return to freezer. Repeat every 30 minutes or until slushy, about 1 hour.