IT IS A HARD QUESTION TO ANSWER. Because it is bottom!Draco, mostly, but not when it involves the main pairing--it's not even remotely switching for them, or ambiguous, or any of that sort. I can't explain further without spoiling the plot but I do think it's worth the read--femmequixotic is a really good writer and the story's a gem.

And to be fair, for the purpose and intent of that particular (and lone) sex scenario/story in general, it was quite appropriate and understandable.