Jen had drawn a couple circles with dots in the middle. Nothing too extravagant, but it seemed this magical marker could interpret what the user was trying to draw, and proceeded to make changes exactly as the user intended. The user this time being Jen, and the victim, good ol' Becca.
Her voluptuous size made for a nice wide target, and though not fat, she would certainly say she was big boned. And grow the tits did. Brand new protrusions filled out from her shoulder blades to her spine, with puffy nipples at the center of each. Just as Becca realized something was wrong, Jen already had one nipple in her mouth and squeeze the other, Becca still balls deep in Julie's face. The new feeling made her reel, a whole new pleasure point being activated in her brain, and caused her still draining balls to work overtime, filling Julie's breasts visibly more than they had been.
The euphoria was intense. Not only was Becca feeling the wholly alien feeling of a cock between her legs, but indeed, the feeling of two new breasts only amplified it. It took her a moment to calm down, slumping beside the bed sideways so as not to damage her new fun bags.
"I have an idea," Becca said, eyeing the marker still in Jen's hands. "We go back to my place. I live alone remember? No worry of having your parents come home and find us in some sort of demonic orgy."
"Okay," Jen said, "but what about her?"
"Julie? Here let me see that." Jen handed her the marker, and Becca strolled over to Julie, eyes still holding the same terrified look it had had since the start. Upon her forehead she wrote a single word: Wipe...
And Julie's eyes went blank, frosting over slightly staring ahead.
"Stand up," Becca said, and Julie complied. "She's completely docile now. Our little play thing, and when we're all done, we can just turn her back, and reset her to before this ever happened." Becca's smeared lipstick mouth curled into a devilish grin, her cock twitching with renewed excitement.