Asriel just laughed. He laughed, and grabbed Chara by her tiny chest and grinned wickedly. "You've finally done it, huh? You've finally just given into your sick desires, and now all you can think about is how much you want my dick..." Asriel then unbuckled his pants, and revealed his thick hog, hard as steel and stretching out further than the length of Chara's body. "Well if you want me to fuck you, I assure you I won't be gentle."
"Oh, please don't, brother! Fuck my ass and abuse me, treat me like the fucking worthless whore baby I am!" Chara pleaded, displaying her tiny booty for Asriel's oversized meat.
"Shut the fuck up!" Asriel roared, very uncharacteristically. "I've heard you tell me what to do for too long, that's all you ever do! Now it's time for you to shut up and let me do whatever I want, and you'll LIKE it!"
"Sorry, master. You should punish me, I've been such a bad baby~ Oh, I still am by talking!" Chara gasped, with Asriel getting entirely fed up and just sticking his large meat into his sister's ass.
His dick dug deep into her, and she just moaned loudly, feeling his cum fill her infantile body.
"Oh, fuck yeah, you feel so good! Even better than what I dreamed!" Asriel moaned. "Yeah, that's right, I dreamed about raping you. Your fat ass and sexy body, I wanted you to be mine... And now that you are, I never want to stop!"
"Nnph... B-but what about mom?" Chara asked. "She'll never accept us... You're a monster, even moreso than usual, and she'll likely disown us for being such degenerates."
"F-fuck mom... If she doesn't like us, I'll take care of her. We only need each other now~" Asriel responded.