Chapter 5: 5
With the fruit successfully fed to Vivi, Robin turned her attention back to tantalizing the girl and building up her arousal all over again. Several hands descended onto the princess's breasts, a set of lips quickly puffing out on the palm of each one as they closed over the quivering tits.
The force-feeding of the Devil Fruit soon faded from Vivi's memory as a symphony of stroking, licking, and sucking played out across boobs that were growing increasingly flushed as the treatment continued.
After several moments, Robin began to feel a quivering through the young woman's skin, one that was distinctly different from how her body trembled as a result of Robin's ministrations.
Suddenly, a gurgling noise sounded from within Vivi's body, one that quickly alerted both women that something was happening to her; struggling to hold back her arousal long enough to find out what was happening, the princess turned toward Robin with a look of uncertainty on her face.
"W-what's happening? I-I feel strange." Rather than answering, the archaeologist sent Vivi back into her pleasured haze as she redoubled her efforts on the pair of tits before her, putting extra effort into stimulating the hopelessly aroused nipples as much as she could.
Within a few seconds, a softer gurgling began to thrum within Vivi's chest; the burbling soon began to come closer to the surface, and in doing so, it began to center in her breasts.
Robin continued her assault on the woman's heaving boobs, knowing what was about to happen and doing everything she could to keep the girl distracted.
Despite having an idea of what was going to happen, Robin was still surprised when Vivi's breasts began to swell.
The growth came in quick pulses, the warm, pale flesh cycling between surging outwards, stopping their inflating abruptly enough that they were sent wobbling uncontrollably, and waiting just long enough for the mesmerizing jiggling to come to a stop before they began to bloat up again.
The princess remained unaware of her predicament, too consumed by the bliss of the arousing treatment she was receiving to notice her tits taking up more and more of her torso.
As the boobs continued to plump up, Robin soon noticed that the younger woman's nipples and areolae were enlarging as well, only their growth was slower and more constant.
Though that change was a bit unexpected, the archaeologist went to take full advantage of it, reaching in with several arms to run the tongues on them up and down the length of Vivi's nearly thumb-sized nipples, as well as tracing the fingers across her spreading areolae as they began to dome out.
Eventually, the size of the princess's tits were approaching the realm of unmanageable, and Robin decided that it was time to bring the swelling of her boobs to a stop.
One of the arms with a hand positioned near her right nipple moved to cover the nub with its palm. The mouth opened, then closed its teeth onto the now fully thumb-sized nipple, biting as hard as Robin could without breaking the skin.
The bite did its job, pulling Vivi out of her pleasure-induced stupor with a loud yelp. When the princess moved to face her captor again, the sight of her own bloated breasts, now each at least the size of her head, came into sight first.
Robin was again glad that she had chosen someplace deserted for this, as the scream that followed would have certainly been heard by anyone else that might have been in the building.
"What is this? What did you do to me? What..." Vivi's frantic questions were put to a quick stop when one of Robin's arms moved to cover her mouth.
As Robin grinned at the princess's struggling, another arm came up to give a light swat to one of her massively swollen breasts, not hard enough to hurt, but enough to set it quivering uncontrollably again.
"I gave you a Devil Fruit, the Milk Milk Fruit to be exact. Everything else was your doing." That wasn't entirely true, of course; since a person often doesn't know what power a Devil Fruit grants, the abilities usually reveal themselves by accident while the user still had little conscious control over it.
Since Robin knew the ability beforehand, she intentionally stimulated Vivi's breasts enough for her subconscious to start putting the fruit's power to use, causing it to pump milk into the woman's pillowy boobs for whatever was so insistently sucking on her nipples.
After allowing Vivi enough time for her panic to settle into confusion, the hand held over her mouth pulled away, allowing her to speak again.
"I... did? I, well, they look nice, and they feel... ooh... incredible. Oh, but can't I shrink them back down?" Robin's grin changed to become even more mischievous as she stalked her way toward Vivi's prone form.