The Importance of Sex in the Roman Empire

Sex is a real theme of what you find in Tacitus and Suetonius. I think sex is important here because Roman women, especially imperial women, were not supposed to be intersex. So the idea that she might be wandering around looking for pay and company is a complete affront to the picture of an emperor's mother. And so why is it sex? Why is it that sex and her sexual appetites, this marriage is the way in which she's being demeaned and brought down?