According to the lovely coed Zarena (played by Zarene Summers) the penis is the hardest substance known to man. She's called into her Geology prof's classroom to discuss the answer she put on a paper where, in this hardcore pic set by Naugthy America, she decides to prove it by demonstration. Taking her teacher's cock in hand she proceeds to show him that with her help there is indeed nothing harder than a penis. And to drive the point home she takes him deep, on the desk, on the floor, from behind, until his stone cock spurts lava all over her lovely face and perfect breasts.