So, I must admit that I was high enough on weed sometimes and enjoyed having sex with a couple of the girls, as well as being fucked by all those boys...”I let my comment sink in for a moment and asked, “I’m a little curious whether you and the other girls have had any experiences with girls? But you don’t have to tell me, if you don’t want to.”Melanie face was turning red, telling me that I had struck a nerve, as she answered, “Well, uh, that’s, I, uh, okay, since you told me so much, I guess I. They speculated, not very seriously, about if any of them had a chance with her. More for bravado, then anything else, they discussed in obscene detail what they'd like to do to her. They didn't know that I'd overheard their conversation and I was too embarrassed to let on that I had.I started looking at her in a different way, and kept getting involuntary erections looking at her breasts. I felt guilty at first but started having masturbation fantasies about her.One morning, when it was later. After a while, the test tube started bubbling and she read off the next set of numbers. We didn't talk about anything but the experiment and I spent the rest of my time trying to think of descriptions for her more clever that 'uppity bitch'.At the end of class, she came around to my side of the table and put her foot on my chair. She rolled up her pants leg to reveal a bit mark. The faint bruise showed still identifiable teeth marks. "Trust me. When fetish bits me on the leg, I know." She put. "Yesssss!" Kathy hissed mournfully, "Spank me, Baby! Spank my ass! Spank it hard! Make it pink! Make it pink!"Smack...smack...smack...smack...smack! Mark's slapping hand soon turned Kathy's ass a bright red and I could clearly see the imprint of his big hand on her firm quivering asscheeks. His cock was a blur as he slammed it repeatedly in and out of Kathy's clenching pussyhole making her moan with pleasure.Suddenly, Mark stopped and whipped his swollen dick out of Kathy's wet clasping pussy..