Answered by Randy Alcorn
I'd respectfully explain that watching such movies violates my beliefs, and ask for an alternative assignment to make up for the time I miss. If the teacher asks for an explanation, I'd say the Bible says God's name shouldn't be taken in vain, and since I love God and want to obey him, I'd rather not watch movies that do much of that.
Also, I'd say Jesus taught that men should look at women as people, as sexual subjects, not sexual objects, and hence he told us not to lust after women. To do so tempts us toward mental and physical immorality. If I were single, I'd say I want to save myself for my future wife and don't want to battle images and memories that might take away from her and my exclusive enjoyment of sex together.
It might help for you to write this down in advance, showing it's not a flippant thing, and that you're not trying to put the teacher down, just that it's important to you to live consistently with your convictions. Make clear you don't want to create an adversarial situation, and you're not trying to judge anyone else, but you just want to do what you think is right. Also, emphasize you're not trying to get out of work, and in fact you're willing to do more work than what you'd be getting out of.
Pray about it and ask others to pray. No matter how the teacher responds, God will honor your decision.
