What is a tie up bikini？
A tie-up bikini is a type of swimsuit that is secured by ties or strings that can be tied or untied around the neck, back, and/or waist. The ties or strings allow the wearer to adjust the fit and style of the bikini, and to remove it easily when needed. Tie-up bikinis are popular because they are versatile and can be worn in a variety of ways, and because they allow for a customizable fit. They are also sometimes called string bikinis or tie-side bikinis.