“Careful of sizing on this one”

“I am 5'5" and 125 lbs. After reading several reviews that referenced an ample backside to this suit, and wearing a size 2, I decided to order the xs. Had to exchange it for the small which fits great everywhere but the bust and neck. The bust is QUITE snug(I'm a 34 C), as is the neck, with the zipper all the way up. The seat area is a little full, but not overly so and does not look bad. I'll keep this one, but I do wish it was roomier in the top.”