In a large bowl, add the sweetened condensed milk and whipped topping. Fold the two together gently until combined, being careful to keep the mixture light and fluffy. Add the lemonade concentrate and continue to gently fold. Do not add too much lemonade that the mixture becomes loose.

Line a 9"x7" pan with one layer of graham crackers, breaking if needed to fit. Spoon 1/2 lemonade mixture over top of graham crackers. Spread evenly over crackers ant top with second layer of graham crackers. Spoon remaining lemonade mixture over top of second layer of graham crackers and spread evenly. Top with 3rd layer of graham crackers. Cover with plastic wrap and store in refrigerator for at least 24 hours before serving. Top with whipped topping and garnish as desired. Serve and enjoy. This can be frozen for up to a month. (I like it better frozen!)