My friend, Lisa, made this for us when we had a BBQ a couple weeks ago. It seems like it would be too sweet but its actually really refreshing. You will not regret trying this!
6 cups water
1 c sugar
6 Tbsp sweet and condensed milk
Juice limes and lightly zest skins into juice. (Most recipes have you grind the entire lime but Lisa was told that it made the batch bitter as time went on. With juicing and only using the zest it does not get bitter).
Mix with water and sugar. Right before serving stir in sweet condensed milk. Serve over ice.