Place water and sugar in a small saucepan and bring to a boil, stirring occasionally. Immediately remove from heat, stir in rhubarb pieces and cover. Allow to sit and cool to room temperature for approximately 30 minutes.

Place cooled rhubarb mixture, peach slices, nectarine slices and orange juice into a large pitcher. To serve, top with Sparkling Pink Moscato, seltzer water and ice. Stir gently to combine.