The key difference is ignorability. If you're not attracted to men you may not even notice that the camera lingers on his chest or she looks down before looking at his face. It also doesn't go on for minutes at a time. Maybe a woman is showing more cleavage that is normal, but the camera doesn't spend five straight minutes panning up and down her body. What exactly does five minutes of looking at grasping hands and contorted expressions contribute to the experience of a film, besides a convenient time to take a bathroom break?