Sex is , well usually, on spur of the moment. People don't plan it when you're in a relationship. That's the key word - if you're a devout Muslim then you'd probably avoid having a relationship in the first place. Those who commit rape aren't devout Muslims, they're just sick men. Men which are found in any community. I find it disingenuous to link these awful crimes to Islam - I would have accepted your argument if these rapists carried out their sick deed had they considered their victims as war booty they won after conquering some city, which is sanctioned in Islam.
Well, I do link it Islam. Or Islamic culture. Because the sexual repression and segregation in Islamic societies creates such men.
I'm Indian... and most of the women in my family... including the religious women... hate arab society. They find the men crude and always trying things and to touch them or grope them. They even hate going back to India... where the men are like that as well.
There is a huge discussion to be had in Islamic socities about dealing with less than perfect people... especially in regards to relationships, sex, alcohol....
Even Islam didn't just come in there are say alcohol is banned. First it banned being drunk in the mosque while praying... then it banned alcohol. Even from the islamic tradition, being practical was there.