Palm Hipster Bikini Bottoms

I bought the halter top of this tankini and absolutely love it! However, I ordered the bottoms in a size medium and though the coverage was what I wanted, the elastic did not hold the material in place and seemed to be for someone larger. I ordered the same bottoms in a small and, sadly, they did not provide the coverage I was looking for. I am a very normal size 6. I wish that Tommy Bahama would make a bottom that is cut with a little more coverage in the back for those of us with fuller bottoms. I know that the style is to cut up and leave the "cheeks" partially out, but this is not a great look for everyone, especially those of us who are a certain age. I am not an old lady and don't want to wear a skirt or shorts, just a bikini bottom that stays in place and doesn't give me a wedgie! I want style, comfort, and reasonable coverage, and while the top is perfect the bottom is a no-go. I had to return and buy a bottom from another brand.