One should not sleep in the same room as a husband and wife, even if the wife is menstruant: Eruvin 63b
Relating the laws of modest dress to the sin in the Garden of Eden: Eruvin 100b
What Rav Ada bar Ahavah did when he thought he saw a Jewish woman wearing an immodest garment in public: Berachot 20a
Speaking about sexual matters in ways that others can hear: Ketuvot 72a, 72b
Being audible to others during sexual relations: Ketuvot 72a, 72b
Rabbah bar bar Chanah reported how he was walking behind Rav Ukva in the marketplace, when a woman who was spinning thread in a lewd way threw down her thread and then asked Rabbah bar bar Chanah, "Young man, give me my thread," and Rav Ukva criticized her non-tzanua conduct: Ketuvot 72b