My parents never talked to me about sex or my period. Even when I started my period, no talks. Just... "Do you have it handled? Good." I ended up losing my virginity at 14 and being very permiscuous. I thought that if my parents didn't care, it really didn't matter. I'm 29 now, helathy, and happily in love with my fiance. He has 2 kids, 7 and 8 who live with us. And I keep telling him he needs to talk to them about the "important stuff" because they're asking questions about boobs and kissing and my favorite... "Do babies come out of your butt?" I had the pleasure of answering that one with, "nope, another place.", "Does the doctor have to cut open the tummy?", "Not always." Well, where does the baby come out of?" "Another place that's next to the but hole.", "EWE!".
We are agreed upon a way of raising them, and that is... Don't give the kid more information than he asks for. If he needs more information, the question will come up, and he will ask. However, there is a time for questions and there is a time for obedience. These particular children have been through hell, and have emotional and behavioral issues. We are trying not to repress them with their questions but they ask at the wrong times, (Like when they are supposed to be doing something they were told.) I will never ignore a question with a sexual reference in it. I WILL answer those because I don't want these kids growing up as confused as I was. AND, I'm sure they will make up their own stories about that too, and want to change how they raise theor kids based on their experiences with me one day. So, I tell them they can ask me anything, and when they're done, I say "Do you have any more questions?" I've made this my habit. Any questions about God or sex take priority in this house right now.
Oh yeah, every once in a while we will have a romantic kiss in front of the kids so they see what true love looks like. So they see that we are happy and in love romantically. If they didn't see him treat me with that kind of gentil kindness, I don't know if they would respect me in the future, being their step mother.