X opens with a young couple having it off in front of a group of middle-aged, upper class women. This gives the impression that we're in for some sort of erotic extravaganza, but hold on...
We are then introduced to two prostitutes, Holly (Viva Bianca), a high-priced call girl, and Shay (Hanna Mangan Lawrence), who is a street walker. Holly and Shay cross paths when their lives become overly complicated in different ways.
It just so happens that Holly needs a third participant for a scheduled threesome, and Shay takes her up on it. Unfortunately, their client isn't just another John, and something happens that results in murder, sending Holly and Shay on the run.
X is less of an "erotic thriller" and more of a straight thriller with prostitutes as its protagonists. As such, it's a head-first dive into the darker side of life. It's not altogether clear if Holly or Shay will survive their ordeal. Don't expect them to be hand-wringing pushovers, though. These are tough women with brains.
X is not at all what was expected, and that's a good thing...