People aren’t actually having sex in Hell, though they’re certainly there for doing it. There are, however, stories of sex. In fact, the whole first circle is devoted to the lustful. In the eighth circle, first pouch, you’ve got panderers or, in plain English, pimps. Thais, a harlot who resides with the flatterers. The most disturbing one is Myrrha, a falsifier of other persons. She was "falsely taking another’s shape upon herself" to "love […] her father past the limits of just love." Incest. You get the point. People aren’t having sex in Hell – that would kind of defeat the purpose – but their sexual behaviors have gotten them into deep trouble.