[119 words]
Harry would understand. It was just a … minor spill.
Ron had tried mopping it up, but the potion had resisted all the cleaning and scouring charms he could think of, and he wasn't going to risk cleaning it up manually.
At first, it had just seemed to fizz harmlessly, but now it was eroding its way through the wooden desk. He could hear the steady drip as it hit the floor, and he knew that it had been successful in places.
Ron left without a word.
It had been an accident; it wasn't his fault. Who kept something like that on their desk, anyway?
Harry should be more careful. It was his own fault, really. What had he expected?