It actually happened to me once, i was telling my friend that i got a boner and i laughed and teacher called me in front of class and i had to hide it with a notebook. And then teacher asked me what was in the notebook. ;_;
....And then i removed the notebook, luckily the boner became a bit soft during all that. So as i removed the notebook, my left hand swiftly adjusted it and pushed it. Right hand handed the notebook to the teacher, left went into the pocket to control the "master wayne". I don't think it was that much visible after this, and hopefully no one noticed expect my group.
She thinks it's a phone and grab it brutally
*drums playing in the distance*
it'd be much funner (for everyone else but you) if it went down the other way
or went up in this case