I have been searching for months for a series that I read part of once and lost! It started with an 18 year old guy that gets a virus from an alien and it changes him physically. Basically it created another human species where any chick this guy has sex with changes too. It spans over quite a few years. It made him really strong and big. The girls can get pregnant whenever they want to. I know it's really vague, but I think it was on one of the hot lists and I want to re-read it! Any help would be really appreciated! Thanks!