I have no idea but I seldom see two porcs in the same general area so I'm going to say false. Would you want to snuggle up to one of them critters on a cold winter night?
The only things I know about porcupines are that I do not approach them and most of the ones I have seen were up in a tree. But they were always alone. I like Grandpa's answer and have wondered how they have sex. It must be a very careful affair.