Second part to Futa-Frisk. Yes, from what I've seen I know Red is technically supposed to be human, but I'd just rather there not be any other humans involved aside from those that exist canonically in the game.
Frisk kissed Red eagerly as she dropped her sword, her lingering rage fading away entirely. Red felt guilty about the cuts and bruises that now covered Frisk, she had gone way overboard trying t take their soul, but Frisk didn't seem to mind, and was all but drooling when Red began removing her clothes; first removing her cape and hood, then slowly undoing her uniform.
Red's chest was smaller than some that Frisk had seen, in comparison to Toriel she was practically flat; though that was anything but a fair comparison. In spite of this, Red was a little happy with herself to see that Frisk still had a tent in her shorts from the sight of her naked form. Her body was well muscled from her training with the Royal Guard, and she looked almost completely human; with the exception of the canine tail that had been hidden by her cloak.
She drew Frisk into another kiss, now working on removing Frisk's clothing as well. Red had to stop herself from pouting when she found that even the human, who was rather short compared to Red, had larger breasts than her. This thought was pushed back in her mind when she saw the human's member, large and throbbing in anticipation. It was hard for Red to believe that she could cause this kind of reaction in anyone, and the sight immediately aroused her.
She reached down carefully, gripping and stroking it. Frisk's moans urged her to continue with her hand as Frisk reached over, gently rubbing her pussy as well. Red moaned with Frisk as they pleased each other with their hands, laying down in the flowers as they continued. It had felt cold moments ago, but now neither of them felt it in the slightest. Red stroked Frisk harder and faster as three of Frisk's fingers pushed into her moistening pussy, pumping into her as fast as Red jerked her off.
Red stopped before Frisk could cum, and Frisk reluctantly did the same. "Don't wanna run out of energy before we get to the best part do we?" Red spoke calmly, even coolly she hoped, but in truth this would be her first time. She hadn't had much time for socializing or sex while training for the Royal Guard and certainly not while she was in it. Red pushed Frisk onto her back and straddled her, shuddering at the feeling of Frisk's member against her.
Frisk could tell that Red liked being in control, so let her go at her own pace. Red lifted her hips, lining Frisk's tip up to her pussy and slowly working her way down. She groaned as she felt Frisk's member push it her, sending small waves of pleasure through her already. Frisk's eyes widened when she felt her tip hit Red's inner wall, realizing this was her first time. She was suddenly twice as thankful she'd let Red take the lad.
Red took a deep breath. No sense trying to be slow about this, she thought, you're supposed to rip bandages off and get it over with right? With this mindset, Red dropped her hips as hard as she could, which was enough force to not only break her barrier, but also hilt Frisk inside of her completely and even hurt Frisk's waist with the force of it. Both of them screamed in an intense mix of pain ad pleasure.
Naturally, both of them were still for several moments after this while they waited for the lingering pain to fade. Once it had, Red began to slowly move her hips, groaning as she felt the entire length of Frisk's cock inside of her. With how deep Frisk was already, each movement sent pleasure through both of them, and it wasn't long before Red was moving her hips faster now, moaning as she rode Frisk, bouncing on her cock.
Frisk moaned, unable to resist the urge to thrust up into her. Red didn't seem to mind thankfully, and even requested that Frisk do it again; which she did happily. Their hips slapped together harder every few moments as they enjoyed the feel of each other. Chara urged Frisk to take more control, to push Red down so they could be on top, but Frisk mentally hushed her and continued letting Red be on top.
'You weren't complaining when Toriel was on top of us~' 'Th-that was different.' Chara said. Frisk could feel her blushing. Frisk mentally giggled as she enjoyed her time with the sexiest member of the Royl Guard she would meet until she entered Waerfall.
Yes, if I ever write Futa-Frisk as a full story, I would have them meet quite a few characters that don't appear in the actual game, such as Red, W.D. Gaster (I would probably go with the Glitchtale interpretation of Gaster unless someone can think of a better one), and even save the other human souls if I can contrive such a scenario. That said, in the event that Futa-Frisk gets another chapter, would you prefer characters like Sans, Papyrus, and Asgore be gender bent to female? Or would it be better to just leave everyone's gender alone? And don't worry about Sans and Papyrus in terms of sex, I actually have a plan that makes lemons with the skeletons possible even if they're female, one that actually explains the games as well.
As for why this was he story to get a chapter, there was no one chapter that got more votes than any other last time, so I picked for myself from the chapters that did get voted for. From this point, only reviews left on this chapter onward will count for the next one, and I'd like to remind that despite the fact that only votes on these chapters are counted, you can still vote for any story idea in Sinful's Drabbles so far.