Yea, they tend to fake it, if there really scream loud, but first they start of with a small moan, then when your getting in deeper and shes getting close to orgasm, she starts to breath faster and moaning a bit louder. She would only start moaning loudly if she WANTS to enjoy it. Either that or your not too experienced. But if she starts to moan softly and breath rapidly then she got more then she expected. Just a thought, and yea, I know that im only 14