After checking out the different kinds of swimsuits and bikinis in the box, you settle on the purple slingshot. It consisted of two thick purple straps that fused to one around the crotch. It was a lot less modest than the others, but at least it wasn't just a bunch of strings.
Feeling both nervous and giddy, you grab the swimsuit and cautiously left for the changing stalls. Seeing no one there, you make a beeline for one of the multiple small cabinets. Inside, you take off your clothes and fold them nicely on a chair.
All ready and set, you grab the slingshot bikini. Feeling the material for a moment, it was smooth and soft. For a moment you imagine what it would look like on a girl. The thought gives you an erection, and now the swimsuit appears even more alluring.
Hesitating for not even a second, you swiftly put it on. It was a bit tight, clearly made for a different body type. Looking in the mirror, you look ridiculous, almost like Borat or whoever weirdo who would wear it. But the sensation of the swimsuit's material sends shivers down your body. Your whole body starts to sweat as a sensation of heat and pleasure engulfs it. You lean your back against the wall as the swimsuit begins to change you.
First, all hair on your body except your hair, eyebrows and eyelashes disappears. Your eyebrows and hair turn a brighter shade of red while your eyelashes lengthen. Next your nails all become clean and shiny, the fingernails becoming slightly longer. Your skin gets a slight tan as it becomes soft, smooth and shiny. Then the pleasure heightens, and your body begins to change to suit the skimpy swimwear.
As you drown in the pleasure, your hands become slimmer and feminine. You run your hands through your hair as it grows down your back. At the same time, your head changes, becoming that of an irresistible seductress with thin eyebrows, a beautiful face and dreamy, slightly pouty lips. Next, your upper torso changes as your shoulders slim down and your waist and abdomen become sexy and curvy. Next your lower torso changes along with your legs. Your hips widen, thighs thicken as your legs and feet slim down to suit the rest of your new body. At this point, you have the curvy body of a red-haired beauty, but with a dick and a flat rear and bust.
Finally, you experience what could only be described as a full-body orgasm as the changes finish. Your breasts explode out of your chest, becoming round, firm and just the right size. Your rear balloons out to a firm and round butt, fitting your curvaceous figure. Your genitals quickly rework themselves, your gonads slipping into your body as they turn into ovaries. Your erection dies down as it turns into a clitoris, with the flesh in your crotch reworking itself to create a healthy female vag, a mound of venus forming as the changes end. You slide down to the floor in exhaustion, breathing heavily in the afterglow of the transformation.
Eventually you regain your strength and stand back up. You open your eyes, looking at the reflection in the mirror. Your new body was the same height as your former male self, but it was clearly female with its childbearing hips, irresistible curves, big, healthy breasts, a nice, round bum and a sexy face. You had long, beautiful red hair and deep blue eyes. The transformation had also altered your mind to fit the new you. Your memories remained pretty much the same outside of one or two obvious changes like your name and somesuch.
"Looking good." you told yourself in your new seductive voice as you smiled confidently. You then tied the sarong your clothes had changed into around your waist and put the pair of sandals your shoes had now become on your feet. You struck a small pose at the mirror and then left back for the bar, your new hips swaying as you went. You were gonna have a good time.