Watermelon and Mango with Lime

Ingredients

• 1 (4-lb) piece watermelon (preferably seedless), rind and any seeds discarded and fruit cut into 1-inch chunks
• 2 mangoes (1 3/4 lb total), peeled, pitted, and cut into 1-inch chunks
• 1 tablespoon fresh lime juice, or to taste
• 1 teaspoon finely grated fresh lime zest
• 1/2 teaspoon sugar, or to taste