Frisk entered the battle with Asgore, king of the monsters, with a smile on his face. Sans had greeted him in the hallway leading up to Asgore. they'd spoken for a bit, and Frisk realized he wasn't even really sure what he would do when he confronted Asgore.

He'd thought about it as he walked forward, and when he saw the king, all the dots that had been left by Toriel, the history he'd found, and the little snippets Chara had let out here and there, came together. Frisk knew exactly what he wanted to do from that point forward.

Frisk walked towards the boss monster, letting his hips sway sexily as he did so. When he'd been with Toriel, they done a little practice with her fire balls whenever they needed a little rest from sex (which didn't happen often, but still) and so Frisk managed to maneuver his way passed the fireballs and get in close to the tall, bulky monster king.

He smiled up at him, feeling his muscles tense from the look, not from aggression, but from trying to force himself to attack when he didn't want to. He didn't want to fight, and frisk knew it. "Can't we just get to know each other a little better~?" Frisk asked, his hands moving under Asgore's cloak and running along his fur, feeling his muscles.

Asgore tried to take a step back, but Frisk moved with him, pressing himself even closer to Asgore, his face against the goat man's fur as his hands moved lower, "So soft and warm~" he purred, as his hands traced lower, pushing passed the line of his pants.

Asgore hadn't been expecting this, even after what he'd heard from a few of the guards around the Underground. Frisk winked up as Asgore cutely, his fingers tracing over Asgore's currently limp cock, trying to wake it. The lust magic mixed with his sexy form was doing a good job of it, and soon it began to rise.

"S-stop this human." Asgore groaned as Frisk pushed the king's pants down, freeing the massive rod. Frisk was shocked by the size. It was already bigger than any of the others he'd seen, even Greater Dog's, and he wasn't even fully erect yet!

Frisk pouted up at him, "Won't even let me have a final bit of fun before you take my soul?" He asked, moving down to his knees in front of the king, one hand holing the tree trunk of a cock up against this face, the other moving down to gently rub against the goat monster's balls.

"That's very rude you know." Frisk added. "You cannot stall like this forever." Asgore groaned at the fondling, his cock growing even harder. Frisk ignored this, looking up at him as he slowly, teasingly, rubbed his face against the thick shaft of Asgore's cock, "Did you ever think about doing things like this with Asriel or Chara?" He asked

The thought bringing Asgore to full stiffness. Chara had been extremely affectionate in the past, and he'd done more than think, and with how much like Chara this human looked.. it was impossible now for any thoughts to bring his back down or undo the lust Frisk had worked up in him.

Frisk grinned, having known this would work from the pictures he'd found in Chara/Asriel's bedroom, and from the the things Chara had told him when he slept, about all the fun they'd had back before the bad things started happening.

Frisk let his tongue move slowly along the king's giant cock, loving how hard it felt. His soft hand continued to play with his large balls, feeling how pent up they were from going years, YEARS without any release, even from himself.

The thought was utterly nightmarish as far as Frisk was concerned, and even if he couldn't sate the king's need to fulfill his duty, he could remind him of pleasure at the very least. He continued to lick, growing more aggressive with it as he did.

He doubted that he'd be able to take the king's entire length in any hole, but he hoped he'd be able to get him off in spite of it. Frisk moved his head back to the tip of the monster cock, swirling his tongue around it before opening his mouth as wide as he could and moving it down to take as much of the pole into his mouth as he could.

Frisk started gagging at just before the halfway point of the rod, and moved off of it for a moment to please him a different way. He moved his hands up, gripping Asgore's cock with both of them and stroking slow and deliberately as his face moved against his large balls, licking, then kissing, then sucking on them.

He could tell this was working a bit better from Asgore's moaning as he went, and he kept going a bit longer. He knew he wouldn't be able to entire finish him off this way though, and had to move back to try taking his cock again, continuing to fondle him below as he began taking his length inside again.

This time he made it to about the halfway point before he started gagging, but didn't stop, pushing forward and taking another inch before realizing that he couldn't take the rest, which was disappointing considering how much of i there was left. But before he could move his head back, the last of Asgore's resistance broke, and he took action. Frisk felt a strong hand on his head, forcing it down as Asgore thrust forward.

The monster king grunted as he began fucking the girly boy's throat, making it his, raping it as roughly as he could. He knew that he wouldn't be able to take it, or at least shouldn't be capable of doing so, but he didn't care. the combination of lust magic and actual pent up lust was too much, and he cared for nothing in that moment other than release.

Frisk realized as Asgore fucked his face like the slut he was that he couldn't breathe, not at all. He could hold his breath for quite a long time, but it was still a scary prospect when he wondered how long it would take the monster king to cum.

Even when he managed to hilt his cock inside of Frisk's throat, likely breaking at least a few laws of physics in the process, he still wasn't at his limit, Frisk went from simple messaging of his balls to gentle squeezing as he sucked for all he was worth, and this, combined with the fucking, got Asgore off a bit quicker.

He groaned, flooding Frisk's throat, or more accurately his stomach, with a torrent of seed. It was thicker, and there than any monster he'd gotten off thus far, and so much filled him frisk felt he might not need to eat for a week afterwards.

Frisk sputtered for breath afterwards, gasping for air as Asgore tried to recover from the climax. Well, recover wasn't much of an issue really. he was so tightly wound that his member wasn't an ounce softer now than when frisk had woken it, and Frisk had a frightening/exciting idea of what Asgore would want to do with it.

Grinning at the monster king, he decided to cut him a deal, "How about this, instead of taking my soul, you come with me back to a certain goat mommy I found living in the RUINS? We can stay there like a family, and you can both use me as your little slut whenever you want~" Frisk moved over, slightly difficult with the sloshing feeling of cum in his stomach, and rubbed Asgore's still throbbing cock affectionately.

Asgore smiled at the offer, "Human.. that sounds wonderful..' Frisk smiled, happy to know he could spend the rest of his life with these monsters... a happiness that was cut short when vines sprouted from the ground, sticking through Asgore in every angle they could, reducing the king to dust.

Even his soul was broken by the attack. Frisk was too shocked to move as Flowey rose from the ground, a grin on his face as he thanked frisk, saying he'd have never been able to steal the souls without Frisk's help. Frisk watched in horror as Flowey brought the six other human souls towards him, absorbing them all at once.