During the '70s and '80s, hundreds of infertile women came to see Dr. Cecil Jacobson, especially since his own eight kids demonstrated that he knew what he was doing, baby-making wise. What they didn't know was that instead of hooking couples up with the anonymous donors created in his fictional profiles, Dr. Jizzenstein yanked into a cup, then put his man milk in his patients' lady parts. Again. And again. And again. Even when it was supposed to be the husband's sperm. But, hell, why would you want some dude's inferior genes when you could have your baby grow up to look like this:
"Jabba, can I have your autograph?"
It wasn't until Jacobson was accused of treating women with hormones to make them think they were pregnant (when he was really just showing them ultrasounds of their own feces) that people started to suspect there was something fishy about the doctor. And that was when people started noticing their kids' resemblance to the man, at which point countless couples looked at each other and said, "You don't really think ...? No, it can't be ...
This is the evolutionary equivalent of steroid use in professional sports.