This is the type of post which usually gets me at least a couple "you're not a parent, you don't understand" comments. And, well, fine, I'm not a parent and I don't understand. But if you want your daughters to have healthy relationships, it's best to not get all weird at the idea that Daddy's Little Girl might have Teh Sexytime one day, especially if you're not quite having the same concerns about Daddy's Little Boy. Yes I know you might want them to delay that experience a bit for good reasons. Yes I know that the actual consequences of sex for girls/women can be a bit more of a big deal. Yes I know that boys/men can be rapey and you want to protect them from that.
But sex is something most of us stumble upon at some point in our lives, your daughters included. You aren't doing them any favors if you're telling them that they shouldn't.