Probably a bigger penis and a hormone imbalance. I would love to see more research on microchimerism and the mechanism or mechanisms for it. if you are unaware women incorporate small amounts of DNA of men who have ejaculated inside of them, how or why this happens is a mystery as I understand it, it's worth noting it can't rewrite her eggs, those are set from her time in her mother's womb, but why else would this mechanism exist if not to cause an effect on reproduction. It's not a pretty thought and my understanding may be about a decade out of date now but if men can be altered by microchimerism from semen in the same way women can, that is potentially pandora's box.