Jude 1:4 (ESV)

4 For certain people have crept in unnoticed who long ago were designated for this condemnation, ungodly people, who pervert the grace of our God into sensuality and deny our only Master and Lord, Jesus Christ.

Lasciviousness [ESV: sensuality] is a shameless exhibit of shameful behaviour. Lasciviousness is open public wickedness with no sense of guilt, no sense of shame, and no sense of embarrassment. Lasciviousness is committing evil and boasting about the evil committed. And when you consider that, you are considering the course of the world in which we live today. It is the wickedness that is all around us, where that which Scripture condemns, is in the world's ethic exalted to an honourable and noble practice, and the shame is put upon those who would speak out against it. But it is not simply the world's system around us. For the fact is, we who are living in this world, rubbing shoulders with this world's system, also possess infiltrations of the world into the church of Christ. And against those we must earnestly contend for the faith.1

John McKnight