The "upside down bikini" trend is a type of swimwear styling trend where the bikini top is worn flipped upside down, with the lower part of the top twisted and tied in the center front, creating a revealing yet fashionable look. This trend has gained popularity among celebrities and influencers and has been seen on social media and in fashion media outlets. Wearing a bikini top upside down is seen as a way to create various styles and looks from a single piece of swimwear.