Fandom: Undertale. Story idea: Futa-Frisk. Includes: Futa-on-female, oral. Warning: Frisk will be referred to as 'she' and 'her' in this story, as she'll be a futa for it. If you can't handle Frisk being gendered, as I know the more embarrassing half of the Undertale fandom cannot for some baffling reason (the character is only genderless so that anyone playing can identify them as that gender, meaning that any gender you assign to Frisk is correct), then feel free to skip this.
Frisk adjusted her clothing before walking the rest of the way back home. As much fun as she'd had with the monsters in the RUINS, she didn't want Toriel knowing about it, it would be too embarrassing. Unfortunately, her embarrassment came in other forms when she actually got to Toriel's house. After Toriel fussed about the one little scratched Frisk had gotten from the encounter with Froggit, before it had turned sexy, she bent over to heal it.
When she did this, Frisk was treated to a view of Toriel's breasts through the top of her dress, much larger than Frisk would have expected. Toriel's eyes were closed for as she used her healing magic, and so she didn't notice Frisk staring down her dress or the tent that formed in her shorts as she did so.
Unfortunately, Toriel did notice when she finished healing her and opened her eyes. "There, all bet..oh my.." Toriel blushed deeply when she saw the bulge, "My child, I'm sorry, I've been thinking you were a girl this whole ti-" "I-I am," Frisk said quickly, "Well..sort of. I'm a futa." Toriel was surprised by this, but didn't seem bothered. She'd heard of futas, just never seen one herself.
"So, this stiffness is..normal?" Toriel asked. "Kinda.." Frisk said, blushing as she looked down. 'Tell her you need her help to fix it.' The voice in Frisk's head, the one that had been there since she had woken up in the flower bed at the start of all this, insisted. 'What? No, that'll freak her out, besides, I don't even want-' 'Oh don't even lie, you were staring at her ass the whole time she was leading us through here. Just go for it, we'll think of someway to back out of it if she doesn't go for it.'
Frisk blushed deeper, looking up at Toriel, "W-well, it is normal, but I'm not gonna be able to make it go away by myself, I-I need your help." "You do?" Toriel asked. Frisk nodded, "Will you help me?" "Of course I will my child." Toriel said, taking Frisk's hand and leading them inside. Toriel wasn't stupid, she knew what Frisk meant by 'help her out', but in her mind, Frisk was too sweet and innocent to actually understand that it was anything naughty, and would likely end up just suffering through it if she didn't do something. She couldn't have that.
She sat Frisk down at the edge of her bed, and politely asked Frisk to remove her shorts. Blushing deeply, and ignoring the voice's smug, triumphant tone, Frisk lowered her shorts, her nine inch cock springing free. "O-oh my, it is much bigger than I would have thought.." Toriel said, taking it in her hand and stroking it gently. Frisk moaned, gripping the edge of the bed as Toriel's hand pumped her cock. Seeing that this manner of pleasure was too slow acting, Toriel moved her head forward, gently licking the tip of Frisk's member to speed the process up.
Frisk liked to think that what happened next had been the voice taking control of her for a few moments, when it truth all it had done was encourage Frisk to do it. She grabbed Toriel's head and pushed it down on her cock more, moaning louder as her cock was pushed into Toriel's hot, wet mouth and throat. Toriel gagged slightly, but knew that Frisk simply couldn't help herself, and so allowed her continue until she came, shooting several hot spurts of thick cum down Toriel's throat.
Toriel, feeling it would be impolite not to, swallowed it all. Face flush, she said, "W-well, I hope that was helpf-" She was cut off by Frisk grabbing her and pulling her onto the bed, "I-I'm sorry, I need more." She groaned as she pulled Toriel's dress up, nearly tearing her panties off when she found them before sinking her cock into her hot, tight pussy.
"O-oh d-dear!" Toriel groaned, gripping the bed as Frisk began to fuck her. So much for Toriel's innocent view of Frisk, but perhaps, she thought, this way was even better.
This was just a snap-shot of what the story could end up being if written. It could contain all genders for Frisk to fuck/be fucked by, and could have any number of kinks thanks to the many different monsters within the underground. If it were to be an actual story, it would likely show encounters for all of the monsters, with certain obvious exceptions.
