I don't care about this conversation one way or the other from a scientific perspective, and I'm not going to sit around googling about sperm in order to take a stance. But I do get the distinct impression that the motivation behind pushing the, "Impure women carry their ex lovers DNA" line of thought in this thread is that it helps some posters to feel better about being rejected by "impure" women throughout their lives.
It's sort of a reoccurring theme. A guy gets rejected by women, so he comes up with reasons why those women are actually unworthy of him. That weird kid who committed mass murder in California several years ago seemed to popularize that line of reasoning. Somebody like that will obviously then seek a reason to claim that the less desirable women (by the most common standards) are actually the most desirable women. "Any smart man would choose the more-pure 23 year old Starbucks worker over the less-pure 28 year old executive." That kind of thing.
