Ah Fionna, I knew we'd cross paths eventually. I think any frequenter of my profile knew I'd eventually get to you. Huh, ever notice how many of my stories start with a phrase being something to the effect of 'Of course I was gonna get to this character eventually'. It happened for Mako, Lilo, Yang, etc. But to be fair, there are some characters that just stand out against others.
Though for some reason I haven't given very much attention to Adventure Time, despite it having pretty much everything i love, in terms of story, action, and sexy characters, and a bonus modifier for having a canon lesbian couple. Well, ex-couple, but anyone who watches the Varmints episode and doesn't get a couple-vibe are either in denial, very unobservant and literal, or just plain old fashion not smart.
As for this story, that's right, I went for a D-girl instead of a futa, despite the fact that 'Futa-Fionna' rolls better off the tongue. I just have enough of a focus on futas already, and wanted to spread things out a bit. Bonus points to anyone who knows the difference between the D-girl and the futa. So, let's begin!
The worlds of Ooo and Aaa were both experiences a few issues. More specifically, they were having exactly the same issue. Two universes crossing paths in the multi-verse wasn't an uncommon thing, it happened all the time, usually resulting in nothing more than some information getting swapped between the two or a few of the life forms getting re-arranged.
But with Ooo and Aaa, the situation was different. The two were more fulled with magic and riddled with dimensional damaged from different disasters in their respective worlds. When the two worlds crossed paths, they just sort of stuck together. Both worlds existed in the same space at the same time, leading to a plethora of odd effects. Essentially, a new universe had been created by the collision of the two.
Some people native to the worlds were gone, lost to the void of space and time, others existed side by side with their doppelgangers. The results of this were particularly shocking for Fionna. Fionna, having been in the exact same place at the exact same moment as her male counterpart when the two worlds came together, their bodies, for a brief period, occupied the same space. The situation could have ended in a number of different ways, and on a coin toss, it ended with Fionna surviving the experience, but with her body permanently changed.
"C-Cake!" Fionna cried out when she first realized the situation, "Something's wrong here!" "What is it?" Cake asked, hurrying over. After everything that had just happened with the world's colliding, so much was happening, and Cake was worried that Fionna had somehow been really hurt or was under attack or something like that.
She was not expecting to see Fionna naked from the waist down with no pussy, a pair of large testicles, and a stiff eleven inch cock, but that's what she saw. "What..the.." Was all Cake could manage to get out.
"I-I felt a weird tingling going over my whole body, and then..this!" Fionna said, her face burning a deep red. Fionna would have been in a state of panic regardless of which part of her body had suddenly turned into a different kind, but the fact that it was her genitals made it basically impossible for her to respond in any productive way.
Seeing that Fionna was verging on panic attack, Cake rushed over to her, quickly trying to calm her down. "Easy, easy girl, I was watching out of the widow, it isn't just you, a whole bunch of things just changed all at once. Something weird is happening, and it got you, probably just some evil spell or something, everything is going to be alright."
Fionna was starting to calm, but the sight of her new member, stiff and throbbing and probably uncomfortable, set her off again. "I-It's so hard.." She whimpered, as though afraid of the appendage itself. Cake clicked her tongue, knowing that Fionna wouldn't be able to function if she kept panicking like this, and she was going to keep panicking as long as she was focused on the freaky aspect of what was happening.
An idea popped into Cake's head. It wasn't necessarily a good idea, but that had never stopped her before and it certainly didn't now. She got behind Fionna, stretching her arms around her body and gripping her shaft with both paws. Fionna tensed up in surprise and paranoia at this, then reflexively moaned at the sudden pleasure that was sent through her as Cake began stroking her cock.
"C-Cake, w-what are you d-doing.." Fionna questioned through her moans. "You need to relax, so I'm helping you. Just calm down and relax~" Cake purred, pumping her paws harder along her cock. Fionna moaned more, beginning to thrust against her hands, wanting to feel more. She could feel the pleasure building up in her new balls, but Cake stopped right before she would have cum.
This made Fionna whimper in the denial of her climax, only for her to cry out in pleasure when Cake took the rod in her mouth and began fucking on it hard. Fionna grabbed Cake's head, forcing it down as she came within seconds, pumping several hot globs of cum into her hot wet mouth. Fionna, unused to pleasure like that, stumbled back against the ball and fell into sitting position, panting.
She caught her breath quickly enough, her rod getting hard again when she watched Cake swallow the seed she had taken and lick her lips. "You feeling better now?" Cake asked, Fionna nodding, "Yeah, sorry Cake, I shouldn't have freaked out like that, I just," "I know, I know," Cake said, "Now come on, let's go see about getting rid of that thing."
Fionna looked down, blushing deeply again, but not in an embarrassed panic this time, "B-before we go..could you..you know.." She stammered, making Cake smirk seductively at her, sauntering over to her and straddling her, "I guess we could have a little fun with it before we get rid of it, but you'll have to be careful not to finish inside, I'm not ready for kids yet."
Yes, that's right, collapsing universes to have a D-girl version of Fionna came to my mind before the idea of just having her be a D-girl without explanation like I do in pretty much all the others.