Pakiṇṇaka 4

The Buddha was staying in Sāvatthī. At that time, Thullanandā bhikkhunī went to the river Aciravatī with a large group of women. They removed their clothes, put them in one spot, and entered the water to bathe. (Thullanandā) came out first onto the riverbank, put on a woman’s lingerie, and said to the women: “Look, does this suit me?” The women said: “We’re worldly people. When we wear this, we want to make our husbands think about love. What use do you have for wearing this?” The bhikkhunīs for this reason went and informed the World-honored One. … She answered: “I really did this.” The Buddha said: “From now on, it’s no longer allowed to wear lingerie. ‘Lingerie’ means underwear decorated with shells, beryl, pearls, jade, gold, silver, gems, or any similar items may not be worn. Even if she just ties threads to make something resembling an undergarment, she breaks a minor vinaya rule. If she has an abscess on the vagina and she bandages it, there’s no offense.” This is called the rule on lingerie.