While the term "amateur" generally stands for inexperience, inexperience in porn doesn't necessarily mean someone's an amateur. Plenty of porn first-timers are born exhibitionists. But sometimes, the term "amateur" stands not just for a lack of a past in this biz, but likely a lack of a future as well. The girls of Amateur Hardcore 13 are fly-by-nights.
The one exception might be Leila Sweet, who delivers a genuine butt bouncing performance.