lubricious

A lubricious movie is one that your mother probably wouldn't want you to see, no matter how old you are. Something that's lubricious is inappropriately or offensively sexual.

Something that's lewd or lascivious, like dirty pictures or skimpy clothing, can be described as lubricious. Occasionally lubricious is also used to mean tricky or sly, like a slick or lubricious used car salesman. A related meaning is "oily or slippery," like a lubricious bar of soap sitting in a puddle of water. This is actually the original meaning of the word, from the Latin root lubricus, "to make slippery or smooth."