Preheat oven to 350 degrees. Break saltine crackers in a bowl, you don't want them crushed, just broken into pieces. Add sugar to the crackers and, then add in softened butter. Work until this is combined and you can press it into a greased 9 inch pie plate. You want to create a well for the pie mixture to be poured into, so press the crackers up the side of the pie plate.
Place in refrigerator for about 15 minutes so the crust can set up.
Next place in oven and bake until the crackers are slightly brown around the edges, about 12 minutes.
In a mixing bowl, whisk the condensed milk and egg yolks together until fully combined, then add the lemon and lime juice and mix well.
Pour the filling into the crust (doesnt have to be completely cooled) and bake for another 15 minutes, or until pie is firm and set.
Do not let the pie burn. Let it cool, then refrigerate for a few hours so it sets up even more.
Top with whipped topping and enjoy!