Our Boob Tape is sweat- and waterproof! Wearing LITCHY Boob Tape under a bathing suit is actually one of our most common uses. However, we strongly recommend you do not sunbathe with the product. Excessive heat or sun exposure can make the adhesive too hot, which can hurt (or burn) your skin. Do not expose our product to prolonged sun and heat exposure.  Do not wear our Boob Tape two days in a row.