Black racerback forever 21 athletic top

Worn a few times, is actually quite flattering but I don’t wear it anymore. No staining under the arms. Has a built in bra as shown, supposed to be skin tight. I believe this is a size small from forever 21 but the tag wore off with washes. I have the same one in grey which is shown to give an idea of the pattern on the black top since it’s not very visible in the photo.