It turns out for women, that if you have sex, you will introduce bacteria into the bladder pretty much 100%. However most women don't get a bladder infection. They empty the bladder, and are fine. New brides had another problem.
The evolution takes place with current sexual practice, which does not necessarily wait for benefit of clergy.
This presents as an unwelcome intrusion into your happy state of being after having clicked with a New Man. About a week later the bladder infection presents itself along with some strange odor "down there". You instantly worry about the dragon eggs prior lovers have graciously bestowed as a gift that keeps on giving.
For those of you who don't know about dragon eggs. A short aside. A dragon egg is something someone leaves behind to explode and catch fire after their departure. This is a phenomenon from an ex, a prior coworker, a relative, you get the idea. They are gone but not forgotten.
You scramble to see the gyn. She/he asks if there is a new partrner, at which time the lightbulb is visible above your head. YES you answer . Ah Ha, says the gyn. NEW MAN SYNDROME.
A urinalysis and std check is in order "just to be safe" and then treatment for the infection. A knowing nod from your gyn, letting you know that your new man is just that, new, and things tend to settle down, make you feel better.
So , for now, the notion that sex is free is slowly waning. You figure out he needs to wine and dine you, pay attention to you and perhaps wait some unwritten amount of time before he becomes your new man. You have various levels of upkeep, check ups, eyebrows, nails, hair and general gorgeous maintenence and make him wait the prescribed period of time. You get it.
Sex is not free.