"Don't you DARE tell me what to do!"
She kissed him passionately, clamping down on him with her demon box.
"Careful what you wish for - you may not get it back."
She smiled sweetly as an aura of purple energy surrounded her. She twitched her nose and eldritch chimes sounded, and suddenly Derek's cock became as hard as iron, and would remain that way for as long as she willed it. For she was the SORCERESS SUPREME and all of reality bowed to her desire!
"For erections lasting longer than four hours, please consult your physician."
A whip cracked in the background.