I lost 20 kg when I was 16 years old. I am now 29 and I have flappy bingo arms at the top And the tops of my thighs are really wobbly as well. I can usually hide it, just have to be conscious of my clothing purchases IYKWIM

Sorry, but I think the only way to rid flappy skin for good is surgery. It's so unfair, you do all the hard work to loose the weight and then your stuck with the excess skin!