He asked what I had in mind for extra credit and said it had to be something to do with biology. I told him I could give him a blow job. He smiled and...told me I needed to be naked. I stood up and slipped off my clothes and walked around his desk. He spun his chair to meet me and I got on my knees between his legs. I opened his pants and started sucking on his 7” cock. After sucking him for a few minutes he grabbed my head and started fucking my face. Finally, he held me tight and shot his load. I pulled my legs even more and at that point my cock was abovemy face. With huge dildo in my ass and my eyes looking in my cock Icould not stand it anymore. I started shooting hot cum all over myface, hair and bra. Feeling of hot cum on my face was so exiting that Icould not sustain and I reached with my tongue for a drop of it thatwas on my upper lip. It felt so good and natural to have cum all overmy face. I knew I need it more.During my high school days I managed to keep my secret and every. The three women who had pleasured me were sleeping in a mass of nudity and intertwined limbs. “What happened to Dr. David?” I asked aloud.“His usefulness was complete,” came the voice from deep within.“Does that indicate my own usefulness is also complete?” “Not at this time. We perceive a threat. You will are required to negate this threat. You remain useful.” It had to have something to do with the activity in and around this building and the underground compound beyond. I attempted to. Resuming her position she carried on stroking my cock as we snogged and we could see when we looked across that Paul was massaging Steffy's clit. I stood and dropped my shorts which left Paul the only one not naked. He slipped off his shirt and trouser and the bulge in his underpants was huge. As he pulled them down his cock sprang back against his belly and I could see Sarah staring at it. He was probably 8 or 9 inches and thick and a he stood there Steffy engulfed his fat knob with her.