Wind the clock forward a couple of years, and when my former 'student', Karen, came to visit me after work one day, it was clear she had graduated with distinction! It was a warm sunny June evening, and I was just getting ready to head home after everyone else had left, when the phone rang, and a somewhat excited Karen said she was just leaving the station, and could she come round and see me. About 6 o'clock there was a knock on the door, and through the glass inner door I could see her dressed in a bright yellow summer dress, and evidently in buoyant mood. I let her in, she closed the outer door, I kissed her on both cheeks and led her into the reception area, where I had already closed the blinds. We no longer worked together and she was very excited about something. I could smell she had been drinking, so I imagined she'd had some business success and had been celebrating - I thought better than to ask. Her light summer dress had no sleeves, was high above the knee, and generally showing a lot of skin! The dress was seemingly held together at the front by two huge matching yellow buttons. She leaned against a filing cabinet provocatively and was getting very flirty, so I moved towards her, touched one of the buttons and said: "So how do these work then?" "They don't" she replied, and folding one out towards me revealed that there was actually a small popper behind each button that held the front of the dress together. I was slightly amazed that she'd gone to a business meeting in such a 'fuck me' dress that was held together by just a couple of flimsy studs. I immediately 'un-popped' them - which was obviously what she wanted! - pushed both sides apart and admired her young slim body - she was wearing nothing else than matching white bra and panties - and that was it! I was hard, and she knew it! Taking me by the hand, she led me out of reception, sat on the stairs, and guided me to stand in front of her. She immediately undid my trousers, pulled them and my boxer shorts down in one movement, and stuffed my erection straight into her mouth.... OMG - I looked down at this previously innocent girl, yellow dress wide apart, white underwear on full display, and her blonde head moving up and down on my shaft. I couldn't fucking believe it. Then just as suddenly as she started, she stopped, saying she was late and had to get home. Quickly pulling my clothes up I said "In a minute, come next door and this time took her by the hand." She followed me, and I lent her against a desk, sliding my hand down the front of her panties, and my fingers straight inside her very warm and very wet pussy...I knew she'd not leave just yet! My fingers worked their magic while we kissed, our tongues probing and exploring each other's mouths hungrily, my hands caressing her 34Bs through her white cotton bra . She always cums quickly, and now was no exception, and was soon writhing against my fingers breathlessly and soaking my fingers in the process. "Now I really must go", she said. I withdrew my fingers, slipped them into her mouth as she was doing up her two poppers. To this day I have no idea what led to her coming to see me, and wondered how long she'd been thinking about it, but now I knew her education was complete - and loved sending her back to her husband squelching between her legs!