Hetero : This is a lubrication educational sequence in which we see that college girls haven't stolen their reputation. This one has a strange way of doing her homework on the table, or rather under the table, since she's far more concerned about the bottom of her panties than about quadratic equations. The only double ruler she lugs around in her bag is a dildo that she sucks complacently before shoving it into her already wet pussy, to measure its depth undoubtedly. She gets more and more aroused and ends up getting completely naked to be able to spread her thighs even wider and screw herself with vigorous dildo strokes. Since she's checked the capacity of her vagina to dilate under external pressure, she decides to try another experiment with her geisha balls. To test their roundness, probably, she stuffs them deep inside her cunt, taking them out and inserting them several times. Judging by her groans of pleasure, it's a successful experiment since it slides perfectly and does her good. That's what's called "donating your body to science"!