Sex scenes are an integral part of the Hollywood movie experience, and these titillating scenes are constructed to make audiences aroused and keep them coming back for more.
In fact, audiences are often disappointed when they see a Hollywood movie that doesn't include a sex scene, so filmmakers feel obligated to include sexiness in every movie they make.
Which is why Hollywood filmmakers become students of scopophilia, mastering the craft of visual stimulation.
As you can see in this video by The Film Theorists Hollywood filmmakers have sex appeal down to a science, so it's not our fault sex scenes turn us on, because Hollywood has been perfecting them for over 80 years.
-Via CinemaBlend