I must admit I do love the sight of a man's balls from behind.
Have you ever noticed how balls are usually excluded from male nudity in movies? Male nudity usually consists of butt shots, not full frontal (although there are certainly many exceptions), but in most butt shots, the balls are not visible, even when the position/angle is such that you should be able to see them.
I suppose many male actors don't want to go that far. They don't mind showing their butts but they don't want to show more than that. (Or the director or producer doesn't want to go that far or is worried about ratings.) An example that comes immediately to mind is Jean-Claude Van Damme's butt shots in Universal Soldier where he is lying on the ground with one leg up and he is clearly holding his balls out of the way so that you can't see them.
A counter-example would be Oliver Milburn in Loaded, in which he gets out of bed and puts his pants on, and you can clearly see his balls from behind.
