Lop the top off of a watermelon.
Scoop out guts and freeze.
Dissolve 1 cup sugar in 1 cup hot water.
1 cup lemon juice (this took about 8 small lemons).
Juice one lime.
Mal and Xav liked this part. I nuked the fruit for 20 seconds or so, left it for a minute, and then they rolled them and mushed them a bit on the table.
Puree frozen watermelon in food processor to make about 3 cups.
Puree some more to eat.
Seven more cups of water and ice.
Throw in slices of another lemon and watermelon chunks.
Hide it from the children because those punks will suck it down so fast that those with a more discerning palate will miss out. People will cry. I'm not kidding.