I'm 5'3", 135 ish, DD cup.  Ordered in medium. A total no-go for me on the bra situation (not nearly enough support, poor shelf bra with shifty circular pads that showed through the fabric). On the plus side, the drapy part disguised and kind of covered that part, but I just prefer more than that. The back felt loose (like it would be bothersome when it got wet, not tight enough to stay up, probably suctioning to all the wrong curves).  If not for the bra situation, I probably would try in Small to see if the back part was better. It was cute enough I might have tried to sew in a different bra, but there
was another option that was fine as is.  My teenage daughter really liked and thought I should keep it.