Ehhhh here we go.
Y/N turned around swiftly, being sure to add enough force in the punch he was attempting to deliver to the strange yet familiar figure behind him.
Jonathan narrowly dodged his attack, grabbing his wrist and twisting it.
"Gah! Why are you here?! I thought you were going to leave Undyne alone."
"Oh no. You see. Me saying that was merely a distraction to keep the two of you occupied. That way you would never see me coming."
"You sick son of a bi-"
"Jonathan?! Why are you here?!"
Y/N gazed over past Jonathan's shoulder, making quick eye contact with Undyne.
Undyne stared back at him with worry, which quickly turned into rage when she realized that he had a firm grip on his wrist.
"Get. Out. NOW."
Jonathan laughed and grabbed Y/N by the throat, lifting him up and preventing him from hitting back, making sure to keep his legs down so he couldn't kick.
"And what are you gonna do about it? Cry? Try to fight back? Come on Undyne. We all know you're way too weak to do anything. So don't even bother trying."
Oh boy, he really had no clue what he just did. Undyne's eye flamed with anger, her irises appearing to be bloodshot red.
Y/N gulped as he knew what Undyne was going to do. It was going to hurt him, but save him at the same time. Undyne ran at Jonathan at full speed, shoving her shoulder up against him. He yelled as he was slammed into the wall, his breath hitching as it was knocked out of his lungs.
Y/N ran over to Undyne and stood beside her, but eventually grabbed Undyne' hand and pulled her to the garage.
"Y/N, what are you doing?! We have to get him out of the house!"
"What do you think I'm doing? Just follow me and you'll see what I'm doing."
Undyne hesitated at first, but finally settled and followed Y/N. Soon enough, they made it to the garage, and Y/N ran to the corner of it. Undyne stared at him in confusion.
"This is no time to play hide and seek Y/N! We have to do something!!"
"I'm not playing games Undyne! Take this, you know what to do with it!"
Y/N tossed her a baseball bat, and grabbed one for himself. He pulled out his phone and dialed the police.
"Hello, this is 9-1-1, what is your emergency?"
"We have a man in our house, and he's been harassing my family for a while now. He assaulted both me and my wife, please send help."
"What does this man look like?"
Y/N gave a quick description, followed by the address. Soon after, he hung up the phone and nodded to Undyne, who then made her way back to where they originally were.
They both ran in, but Y/N stayed on the bottom floor, while Undyne went to the second floor. Y/N hid behind a wall, waiting in case Jonathan just so happened to walk by. Undyne walked carefully to where she attacked him at, finding him there, still lying on the floor.
He got up and laughed.
"You......you deserve to die......Y/N....he's just using you for your looks. Now why don't you come back with me, and I'll only punish you a li—"
"NO."
Undyne held the bat tightly in her hands, keeping a watchful eye on Jonathan. He looked at her in disbelief and hatred.
"What?"
"I'm not going back with you. Never again am I going to be able to forgive you. So just, leave. No one wants you here."
"Oh come on Undyne. We both know that you're only pretending to be strong so I can't see your weaknesses. Well guess what? I know you Undyne. Deep down, you wish you could just cry and come back to me. You beg for me every night."
He stepped closer to Undyne, raising his fist.
"So come back with me, or else, I'll just kill you right here and now."
Undyne stepped backwards a bit, gritting her teeth harshly. She tightened her grip on the bat, and raised it above her, as if she were about to swing at a ball. Jonathan laughed and shrugged. He ran at her and swung his fist, only to have his face greeted by the sudden, "CRACK!" against his jaw.
(Ooooooh, Undyne just broke his jaw)
Jonathan yelled out in agony. Y/N, who took Jonathan's yell as a signal that Undyne has him, raced up the stairs, ready to attack. He sighed in relief, however, as Undyne just stood there, hovering over the now badly bruised Jonathan, who had blood trickling down the corner of his mouth.
"You....you only did that because yo-"
"SHUT UP JONATHAN."
Y/N was slightly surprised at how serious Undyne's tone was.
"I don't care what you say about me or Y/N. He loves me for who I am, and he would never, EVER, pull the same bull that you pulled on me. That's why I love him, and not you. So I hope you have a fun time in prison, @!$?."
Soon enough, the police arrived, and gladly took Jonathan away. Y/N and Undyne were told that no charges would be pressed against them, as they were only using self defense. However, they'd have to go to court, just to make 100% sure that nothing else was happening.
And about a month later, after the trial, the two went home.
Y/N was continuously congratulating, supporting, and comforting Undyne about staying strong throughout it. Undyne loved it.
And although Undyne still is worried what might've happened if she hadn't had swung, she still remains happy and as energetic as always.
Finally, the two were safe for good.

YOU ARE READING
Undyne x Male Reader
Fanfiction[OLD] Fall in love with the one, the only, UNDYNE! Yes indeed, guaranteed with this book you get a girlfriend, then a wife, then an adventure! Read now for the low low price of only $0.00! You heard me! $0.00! Hurry up and read now!