You and Regulus were preparing for the upcoming NEWTs.

Well, to be fair, you are the one that needs to study for it. Regulus would do just fine. He probably noticed that you were in need of preparation, because in the last class of the day, he slid a note across the desk that said: If you'd like, we could meet up in the common room and study at 8pm. You, not wanting to fail, give a small nod in his direction.

In the Slytherin common room, you and Regulus take a seat in the corner, sitting on top of two cushions, placed on the thick carpet. Regulus writes a few questions down that he thinks might help you prepare for the end-of-the-year test. You watch as he writes on a fresh piece of parchment, in that neat handwriting of his. After he finishes, he hands it over to you, while saying, "Here, answer them and I'll correct you after."

He goes back to his own studying, reading through the textbook as he waits for you to finish.

After around ten minutes, Regulus looks up from the pages of his textbook, and notices you haven't even started and you just sit there, fidgeting with your fingers. He sighs, before saying, "Y'know, you're going to have to start somewhere, right?"