What Have I Done?????!!!

As a mother, I feel it is my duty to raise my daughters with the knowledge that they are beautiful daughters of God and they should act as such. My husband has lovingly resisted the manly urge to teach his children the art of "pull my finger," "the scratch and adjust," "you should see what I left in the toilet, no really, come see it," and belching the ABC's. I am far from a girly girl, but thought that I could teach my daughters how to behave like ladies.
This last week as Nick was out of town for work, I found that my daughters are as disgusting as they can be.
Katlyn came home laughing at how grossed out the boys at her table were when she farted during the math test. When I asked why she couldn't do her stinky business at another time when not so many were around, she got very serious and said, "My tummy was hurting, and you said never to do anything to hurt myself." Even as I tried to explain that her behavior, while not bad, was not pleasant for those in smelling range she just laughed and went back to doing her homework. I gave up trying to convince her of the benefits of ladylike behavior and I went back to doing dishes.
Kara, who would never fart around anyone if she could help it, is fascinated with poo. how someone could hate gas, but love poo I have no idea. She has taken to leaving the toilet unflushed just so she can share her hobby with everyone else in the house.
Valentina, while young and innocent, almost always has her hand in her diaper. Granted she has eczema on the inside of her leg, just inside the diaper line, but it never looks good to see a little girl walking around with her hand down her pants.
Eva thankfully has no bad habits yet, but I am sure they will come...
What I do wonder is where I went wrong? I have tried to be a good example to my girls, Nick has not taught them anything objectionable, and manners are a must in our home. The only benefit is that when these girls are teenagers these habits may repulse boys and I won't have to worry about them. Though Nick warns me that boys like girls who fart and burp and do all manner of disgusting things. ....there is no way to win.