Bikini emoji is the picture of the 👩 Women’s swimming suit, consisting of two parts. This type of swimwear is associated rather with 🏖 Beaches, vacations, and bathing in the sea than with 🏊 Swimming sports or anything else, so no wonder that it is most commonly used exactly in these meanings. In such a context, it may be often followed by other vacation- and 🌻 Summer-related emojis like 🕶 Sunglasses emoji. Also, it may be used in the context of fashion and beauty, as well as in the context of shopping and it often appears together with other similar emojis. (Source: Emojis.wiki, Fair use)