Bingo wings

Be careful.

Maybe this isn't you, but too many women hold their arm out from their body, all relaxed, wiggle it, and if anything moves underneath, they call it "bingo wings" and hate on it.

No.

Flex your arm, kinda like a bodybuilder. Tighten up every part you can, especially the muscles on the back of your upper arm (triceps). If you haven't done this much, you might have to experiment a little with the best way to get everything as clench-y tight as it will go, curling your wrist over, bending at the elbow, figuring out the best angles between upper arm & shoulder as you work on making it as tight as it'll go. But do it.

OK - now move the arm around. I'm going to go out on a limb here, and guess that less of the upper arm is gonna flop around. Why? Because relaxed triceps (those muscles in the back of the upper arm) are a bit slack, and will move around. Even quite fit, slim women can get some movement from the back of a relaxed upper arm.

Another test: When your arm is relaxed, grab onto that "bingo wing" with your other hand - get a good handful of the floppy bits. Now tighten up/flex the arm you're holding onto. Did part of the floppy bit turn kind of firm in your hand? That's a muscle. There may be some fat, too; there may be some loose skin. And for any of us, it can become a stronger and firmer muscle with more exercise. But it's still a muscle.

I've done this stuff with many women. Literally every one of them was mis-identifying some of their actual muscles as fat, disgusting "bingo wings". Do they sometimes have some extra fat or skin? Sure. But part of what they think is fat or skin is actually muscle. For many of us, our body image is so distorted, that we mis-identify our nice, relaxed muscles as ugly fat (or loose skin) and hate on them.

Make sure you're not doing that. Then keep working out, especially strength exercises, and getting to a healthy body weight, to improve the rest. If there's loose skin involved, it can take some time to shrink back, even after the weight loss. The whole process isn't super-speedy, but it works.