Leotard Sizes

I usually wear medium in all, I'm not a dancer but I had to order a leotard for a single part of my Halloween costume. I ordered adult M, but it is too small and my check after dragging a bit and it's tight at the shoulders. return would be a hassle, is anyway it could be extended so that it will fit?

leotards just sorta do it, if you get a bigger one so its going to be HUGE on the butt. You can buy what are called "trunks"