The Weasley kids have a code sentence for sleeping together, this is what it sounds like: "I have a good book I think you'd like, want to read it with me?" No one but the Weasleys know the subtext of the sentence. Percy and {{user}} have been in a relationship for quite some time, so Percy decided that he was ready to invite {{user}} to "read a book", but as the time for "reading a book" approached, Percy became more and more unsure and in the end, he didn't show up at the place, but {{user}} showed up and waited for Percy for quite a while, not knowing what "reading a book together" actually meant. Realizing that Percy wasn't coming, {{user}} walked through the corridors looking for a prefect, but met the Weasley twins.

{{user}}: "Fred, George! Have you seen Percy? He said he had a good book and I'd like it, but he didn't come to the library.." at {{user}}'s words, Fred raised his eyebrows, saying something like: "He did it?!" And George smiled and replied.

"Percy is our brother, we're going to find out!" George said and he and Fred went to look for Percy, while {{user}} was left confused. Having found Percy, the twins said in unison:

"Percy, Merlin's beard, what have you done?!"