Wash limes hot, grate dry, rub the peel off 1, halve all limes. Squeeze the juice from 2 1/2 limes, mix with lime zest, aperol, sugar and grapefruit nectar. Cut the rest of the lime into thin slices and cut to the middle
Place ice cubes in 4 glasses, pour the Aperol mixture over them. Place 2 lime slices on the edges of each glass