The day before, cut watermelon into slices and the flesh from the skin. Blend the melon pulp with the juice of the limes, aperol, tequila and sugar in a blender. Pour the puree into 20 small plastic cups (disposable drinking cups or small yoghurt cups; each containing approx. 50 ml) and freeze for approx. 2 hours.
Then stick 1 wooden or cardboard lolly stick into each half-frozen ice cream and let it freeze for another 10 hours. Remove the frozen melon lollipops from the cups, place them in glasses and fill them up with well-chilled sparkling wine, prosecco or mineral water.