Kepha,
Always do what the saints would do. Would a male saint ever find it acceptable to watch a movie that contained female nudity? No! Our goal in life is to be holy. One of the reasons the saints became holy was because they went to great lengths to protect themselves from sin entering through their senses - sight, sound, etc.. There was one saint who was very handsome and in order not to fall into the sin of vanity, he never looked in the mirror. Another saint, while baptizing thousands of women, never once looked at their face so as not to risk seeing a beautiful woman and fall into the sin of lust. These may seem extreme but even Jesus told us to be extreme when it came to protecting ourselves from sin and occassions of sin ("And if your eye causes you to sin, pluck it out, and cast it from you. It is better for you having one eye to enter into life, than having two eyes to be cast into hell fire". - Matt. 18:9)
If a man purposely puts himself in a situation where he sees a naked woman he is putting himself in an occassion of sin (a woman's nakedness is always going to be a source of temptation for men because of concupisence). The Church has always taught that "to willingly put yourself in an unneccessary proximate occassion of sin is always a mortal sin." It doesn't matter if you commit a mortal sin of thought or deed as a result of being in the occassion of sin or not. Just because you knowingly placed yourself in unneccessary danger this is a sin already.
"The lamp of the body is your eye. When your eye is sound, then your whole body is filled with light, but when it is bad, then your body is in darkness. Take care, then, that the light in you not become darkness." (Luke 11:34-35)