Hermione’s straining ears just picked up Remus Lupin’s embarrassed voice through the door. It was his code that he was himself and not being coerced, if he had to approach the house from the outside for some reason. Fred and George had picked all the passwords – god knew why they had been allowed that job – and Remus seemed to grit it out reluctantly each time he had to use it. She’d heard him complaining to a cheerfully unsympathetic Tonks that it was "childish’. The twins had a betting pool going as to how long it would take Remus to break and demand a new password.