Danielle quickly answered her boss/master's summons, taking the pen with her. Though Dave knew that she shouldn't give him the pen (she'd already made herself into Danielle, his magically submissive slave/secretary), that knowledge couldn't compete with Danielle's desire to both please her Master and to give him absolute power over her. Sure, as of now he could command her to suck his cock, or insert a vibrator for the rest of the day, but with the pen? His power over her would be complete.
Which was why the male mind of Dave found itself helplessly watching through Danielle's eyes as she knelt at Joe's desk and gave him the pen that could control reality.
"Master, I must give you this pen," the submissive girl said, staring at the floor, not daring to meet her Master's eyes. "It is very powerful. Whatever it writes becomes reality."
Joe rolled his eyes. To his memory Danielle was always coming up with these roll plays. He supposed that is sharpened her experience somehow, but all he wanted was to have her hot and bothered at his beck and call. Still, he played along, knowing that keeping his slave happy was key to her continued enslavement, and that lunch hour blowjobs were worth a bit of roll play. Still, "And what would happen if I wrote that my slave had bigger breasts?" He'd been after her to get implants for months, even offering to offset some of the cost, but the petite girl didn't seem interested.
"Simply write it and see, Master," she replied softly.
Inside, Dave was shaking. Joe would write what he wanted, and the pen's secret would belong to a someone other than Dave. Not to mention the fact that the petite frame of Danielle was about to get even more unbearable. Dave knew about Joe's obsession with tits, they'd watched the women in the office before and even commented on some. He knew Joe wouldn't hold back. Just then, a tingling in his chest stopped his thought process and he watched with trepidation as his, her, Danielle's breasts began to slowly expand, looking shockingly like two water balloons being filled slowly.
Joe finished writing "Danielle's breasts will grow to C-cups," on a piece of scrap paper and was about to tell the girl that he'd made her unable to orgasm without permission, a game they played often enough, when he heard the girl squeak. Turning to look down on the kneeling figure, his eyes widened as he watched her breasts grow, stopping after a minute or so at what could only be a C-cup. Slowly he stared at the pen, then back at the girl. With this he could really have fun.