Wash fruit. Cut into thin slices; remove seeds. Place lemon slices in a large bowl. Cover fruit with sugar. Let stand 10 minutes, then press firmly with potato masher to extract juice. Add water, continue to press fruit with masher until liquid is well flavored. Add ice cubes.
Taste lemonade for sweetness when it’s chilled. If you wish, add more sugar and stir to dissolve. Pour over two ice cubes in tall glasses; add lemon slices to each glass.