From livejournal's 11_reasons community, theme table 3, prompt #30 room/location/place.

Oliver felt somewhat guilty that he didn't remember Rachel when he met her for the second time. And if he was being honest with himself he knew why she was entirely forgettable to him the first time; she was just another Quidditch groupie, or so he once thought. A girl that had tried out for the team that Oliver had no real plans of changing the line-up to anyway. They had a great team running, one that had defeated Slytherin and try-outs were only held at McGonagall's request to pad the reserves with talent, "just in case", as a captain was wont to do. But she hadn't made the team, nor had she made the reserves, and looking back now Oliver did feel a little ill realizing that she was the only one who didn't.

Out of some strange sense of obligation (and a deeply buried fascination) he began to seek her out during the day for random conversations; a quick hello between classes, a friendly chat before or after meals, and soon he began to see her at the door to his office, which he held in lieu of a classroom. Then they were spending hours after classes talking about school, life, ambitions. Next they began spending their weekends lazing around on brooms, strolling around the lake, or if it was a Hogsmeade weekend, getting a sheet or two to the wind on delicious butterbeer.

Oliver never had any proper conversation with Minerva about the subject about getting involved with a student, but shortly after he became aware of Rachel the second she walked into any room, he started to receive a series of the most terrifying glares from the Headmistress and he knew right quick that he was fucked.