Mmmm the mandrake one wouldn't really work. They may not be able to hear it but the vibrations of the scream would still be the same and could still cause a deaf person to die of it results in hemorrhaging in the brain.
15 Times Tumblr Proved Muggleborns Are The Coolest Kids At Hogwarts
And he actually drops the towel (because come on guys this is JAMES POTTER we're taking about) and lily squeaks and her face goes redder than her hair. A wolf whistle is heard from Sirius' bed and Remus just shakes his head with a smirk.
I understand that they had to cut out the parts of the book that had less action and were less important to the plot, but those were the best parts because they just could sit back and make jokes with each other (usually) without angst