My H was/is the same in regards to our kids. He heard they were having problems form me (dismissed it immediately, I was paranoid), from their teachers, my parents, doctors, councelors, friends... He even avoided talking to them about it and giving them vague answers to their shy questions until they quit. Their C had to call him in twice to tell him to talk them, he still HASNT!!
But, there are some quiet moments when we face the truth, when we are alone, in bed, stressed. Of course how we proceed is another story but believe me she knows. Hopefully she will act accordingly sooner than later. And if she doesnt, as your s will grow up, he will bring her face to face with her actions. Dont doubt that. Keep doing what you are doing, xxx K