Every so often the university will send me a student for a private lesson, which is how I found myself in my office with Penelope Cum. Penny was progressing well in her studies, though her knowledge of the muscular system was lacking. We went over a few muscles, and I grew bored. My attention was piqued when she asked about reproductive organs. I offered to show her my balls as a joke, but shockingly, she accepted. I pulled out my genitals, and she got close to inspect them...then asked to lick them! I wasn't about to say no! Penelope got a face-full of knowledge giving me a blowjob, then made me even harder when she showed me her big tits and ass. We fucked all over my office, then I came in her mouth...but she was so sexy I was immediately rock hard again! I fucked her doggystyle on my desk, then she swallowed a second load!