He did stir when he heard a familiar sound. Could it possibly be the rustle of the bag of papaya treats?
It was, and Weasley came out to munch a few treats. Yum!
He stuck around briefly for some nose rubs.
And then slithered back down into the cushions with the lose change and stale cheerios.
I'm willing to bet that your couch cushions aren't hiding anything half so fine....