I wore this dress just one time for a vacation and then washed it right after I used it (hand washed and let it air dry). It is not see thru at all and it has a built-in white slip. I did not have to wear a bra or any breast undergarment. I’m typically a size 4 or 6 in dresses and it fit perfect. Beautiful dress for a tropical vacation! What questions do you have? ❤️