Divination book title

[kemper]

> > Kemper:
> > Ron: Can I have a look at Uranus, too, Lavender?
 
> Geoff:
> That isn't really a sexual double entendre. It's the sort of infantile humour that (usually) boys produce in their early teens: references to breaking wind, sharing "naughty" words because it's the frisson of  doing something about which your parents would throw a fit...

Kemper:
No matter how infantile or juvenile the humor, the humor Ron uses is a sexual double entendre. :-)

And since Ron uses it at 13, I'm guessing that Fred uses it as well in OoP when he's talking about the fifth year being difficult but that he and his brother "managed to keep their peckers up".  I know that the phrase is old fashioned and is equivalent "keep their chins up" or "keep their spirits up", but doesn't pecker have another meaning than one's nose in the UK?  If it does, then I think that JKR would have Fred use it with that intended innuendo. 

If Percy were to say it, I don't think the naughtier implication would've been intended because it doesn't seem to be in his character, but Fred and George seem a bit... bawdier? ...that's not the right word.  Maybe more infantile than Percy, and so it's easier to believe they mean something else other than the original meaning of the phrase.

Kemper