No - when I go down on her, it feels much better than that! ^^* But seriously... I assume you're referring to her response, which hardly seems unusual or over the top, so I see no reason to think that she's faking it.
Nice, but you've got to love this quote: "...laughter is a welcome element in the amorous play between a man and a woman" (1:20-1:25), which is then followed by zero laughter -- not even a slight grin from either one of them! *LOL*
But seriously... I assume you're referring to her response, which hardly seems unusual or over the top, so I see no reason to think that she's faking it.