After awhile our normal swim turned into a water fight, with Madiie's top coming off and her blushing deep red as I took a quick glance at her chest b...fore turning around to give her some privacy. It didn't escape my sight that her nipples were very engorged, serving to only make me turned on at the idea of Maddie possibly being horny."You can turn around now! Did you see anything?" Oh of course not Maddie, I'm a gentleman." Liar!! Hahaha!"Maddie playfully came towards me and splashed more. .. one kid came down, took out a camera and took pictures. That started a rush. And arguments. The Japanese and Chinese students and were at the boards defending the math against the ANZAC’s ... the Australian and New Zealand students.Then ... from a door off to the side ... emerged the lecturing professor ... his classroom.“What the hell?” he shouted. “What’s going on?” And he caught sight of the math. In seconds he was as deeply involved as the students.The Registrar opened the door and. " I said this clearly, carefully saying every word so he was sure I was consenting to being fucked by a stranger.He pushed upwards, I felt his cock probing at my pussy, and then with a single thrust he buried himself inside me. I was sure my scream of pleasure would bring a curious neighbour but next we both just took a deep calming breath at the same time. He felt so long and thick in me, filling me once again."Holy shit. Fuck me with that cock." I almost shouted.He did so, rapidly increasing. I’d never do anything with her. You are…well, I like being with you.” I finished lamely. A look of relief, and happiness lit her face. She leaned forward and kissed me quickly on the lips. “It would be fun to see her face.” she quipped, her evil smile appearing. “Now be a good Big Bro, and put some lotion on me please.” “Anything for you, Little Sis” I replied, getting up to retrieve some lotion from a table nearby. I returned and sat on the edge of the lounge chair, next to her legs. .