You can see that the girl wants to, but as I understand it - her mother did not often let her go to parties. Slim and pretty, she wants to have sex and get off like a grown-up! And the guy's got a big dick, and he handles it like a man. The little sweetheart's got a hard-on. But she's riding his dick with gusto. I'm telling you, she's got potential. At the end of it, she's getting fucked in the ass! She's just twitching in ecstasy.
Just an insatiable mistress caught, not against having fun with a temperamental male.