I have to ask: where did you go to school? I'm guessing it was western Canada, probably Alberta. That conclusion has absolutely no scientific basis, unless you think that the 12th century was the best century and the Dark Ages were highly scientific. It sounds like one of those Christian theories where you're just supposed to agree because it's another Christian putting it forward, like the idea that bananas are perfectly geared towards people eating therefore God exists, or that there is no homosexuality outside of the human race. The idea of someone actually teaching that in a school is extremely disturbing, and morally wrong.
It's like saying that people can't get aroused during a rape-- they absolutely can. I had a friend who was raped when he was 13, and he actually ejaculated during it... all that it did was make him even more screwed up. People can get turned on by the idea of being infected with AIDS for crying out loud...
So yeah, I guess my point is that I really don't think that human sexuality is geared towards so-called 'pure' acts of love... as much as some groups would like to believe that we all want only to find the heterosexual partner that God intended us to be with, and make love daily in the missionary position with our eyes closed and thinking of Jesus, the fact that we can't always control our sexual impulses/what arouses us is a big part of what makes rape so horrifying.
I can understand being anti-abortion, but spreading ridiculous lies and ignorance, and then teachers hearing those and repeating them really pisses me off. Seriously, it actually sounds like an argument in favor of rape.