The following week I had a surprise invitation which was to deepen my bi experiences in a most fulfilling way. Prof Richardson had been my personal tutor for more than a year and it was not unusual for him to continue a discussion paper in our local student pub. It was more relaxing in the informal atmosphere of barroom and booze although not very much was drunk. Professor Richardson was in his early fifties, tall and distinguished looking in such a way that he appeared attractive even to some of the younger female students. No doubt furtive fingering under the bed sheets often took place with the Prof in a starring fantasy role. But on this particular evening after a lengthy discussion about the toleration of Ancient Greeks to a range of sexual activities, he made an offer which was to change my life and introduce me to new levels of sexuality. It seemed harmless enough at the time : ' My wife and I would like to invite you over to dinner tomorrow night if you would like to come.' I was surprised at the offer but accepted anyway, funnily enough looking back I am sure that a tremor went through my cock at the time, as if it recognised something I hadn't. The next evening at seven o'clock I was welcomed at the door of a large terraced Victorian house by the Prof himself. ' Come in Michael, come through and meet my wife, she's keen to meet you.' I followed him down a high ceilinged hallway into a dimly lit sitting room containing two large sofas. ' Michael this is my wife, Dr Richardson.' 'Please call be Sophie' she replied in a posh voice. The Prof's wife was in her late forties with dark tied back hair, high cheekbones and beautiful deep brown eyes, but what struck me most was the size of her breasts. They seemed enormous as the top of her maroon dress vainly strained to contain them. A tingle went down my spine , between my legs and into my balls. She was shorter than me and what I saw of the rest of her body it seemed firm and tanned. All through dinner my eyes kept looking at those huge breasts, I fought hard against staring but my cock uncontrollably swelled, bulging against the constraint of my trousers. If I stood up I would have knocked the table over with my erection. It was towards the end of the meal when we were sipping wine and talking, that the Prof revealed his intentions. ' Michael you have been staring at Sophie's breasts all night would you like to see them?' Before I could reply Sophie raised her hands and unclipped a clasp at the rear of her dress, then she skilfully pushed her bra strap off her shoulders. The two breasts with their hard pink, up turned nipples spilled out and almost drooped to the table itself. My mouth opened in amazement, as the Prof's amused comment ' I think he does!' echoed round the room. 'Michael , follow me' Sophie murmured and I walked slowly behind her into the sitting room. Once inside she sat back onto a pile of cushions and patted the sofa beside her. Before I could join her the Prof spoke again. 'Let's get naked first.' Awkwardly I removed my clothes, aware that my big cock was swelling to its full size as I did so. ' You've got a weapon there...' Sophie whispered softly in her posh voice as she stripped and stared at me at the same time. 'I think you should prepare her with your mouth Michael.' the Prof encouraged me as Sophie laid back on the sofa and opened her legs wide. For a moment I gazed at her cunt, it was very different from my girlfriend's pussy. The lips were larger and stuck out from her slit, she had tufts of brown hair on the mound above whereas my girlfriend's was totally shaven and Sophie's clit was fuller and more pronounced. I knelt down and started long licks gliding from her arse hole and up along the full length of her cunt. I avoided her clit and concentrated on the lips and around her hole as I didn't want her to cum too quickly. When her murmurs developed into one long whine, I then focused on her clit. I moved my tongue up and down and then round and round. Sophie started to move her thighs in time with my mouth, and then grunting she seized my head and pulled my face hard against her cunt, I felt and smelt her juices as they soaked my face. Suddenly I felt Sophie's hands grasping my cock and I thrust forward as she cried ' Fuck me. Fuck me. Fuck me.' My cock easily slid through Sophie's cunt lips and up her fleshy hole. She gasped out a long 'Aahh' as I felt my cock wedge in deep. And then I started. In out. In out. In out. I quickly fell into a rhythm as I pounded away. Sophie's cunt was a lot looser than my girl friend's and there was much less grip, so I reached round and grabbed her buttocks so that I could keep my rhythm going. Sophie was muttering a string of filth as I fucked her even faster. Then I felt a hand moving between my legs and fingers gently jiggling my balls, with each thrust they softly squeezed and held on no matter how fast I fucked. It was the Prof. Then his hand was gone and a few seconds later I felt a finger rubbing against my rectum. Gradually it was pushed up my arse hole and with each thrust I made into Sophie it went deeper. Then it reached my prostate gland and tormented it with circular motions. It was impossible for me to hold back and I shot a huge hot load into the depths of her cunt. My balls felt as though someone had shot a bolt of electricity through them as they were drained of the last drop of spunk. I collapsed onto Sophie's huge soft breasts and behind me I heard the Prof say ' Let's have a drink, we've only just begun.'