Wash the limes well, then cut off the ends and cut them into quarters.
Add the limes, sweetened condensed milk, sugar, about 3 cups ice, and 3 cups water into a high power blender.
Blend for about 20 seconds (you don't want to overblend).
Strain the mixture through a fine mesh strainer.
Serve over ice with a shot or 2 of your favorite spirit (I used @titos vodka! But gin, tequila, or rum would also be good).
Use a straw to mix the alcohol in and garnish with a lime wedge.
