the other problem is that even if you do start into a monogamous relationship you've no real way of knowing if your new partner has or has ever had an sti apart fron both of you getting tested at the beginning. Maybe some gay people do this but i dont think a lot of straights do? I think the girl generally just goes on the pill when the sex starts to become regular and thats it? Just the impression i get from my friends, perhaps people in their 30s are more careful?