Sister learns to attack the sack

*(This story is a sequel to "*[*Sister sack-whacks*](https://www.reddit.com/r/BallbustingStories/comments/1b0579m/sister_sackwhacks/)*". All characters are over the age of 18.)*

"Remember when I kicked you in the balls?", Jacob's sister Emily asked him.

Jacob did in fact remember, though he didn't really like to think about it. It had been the previous summer, when he was back home from college and his sister was on break after graduating high school. They had been horsing around, and things had escalated, and Emily had booted him in the nutsack by accident, sending him down for the count. Afterwards, Emily had promised never to hurt her big brother's testicles again.

Now the two of them were home for Christmas break. Their parents were out of town for a couple of days, so the siblings had the house to themselves.

"Uh, yes. I remember that," Jacob said uncomfortably. One had unconsciously went down to protect his balls. "Why do you ask?"

"I was wondering if you could teach me how to do that to a guy," his sister muttered, looking embarrassed. She was slender and blonde, with a cute pale freckled face.

"How to kick a guy in the balls?" Jacob asked. "Why do you want to know that?"

"Well...there's this guy in my dorm named Bryce," Emily explained hesitatingly. "He's really cocky, and he thinks I should sleep with him. I don't want him at all. But he thinks he kind of owns me. Every time we're together, he puts his hands on me."

"Puts his hands on you? How?" Jacob asked, his face darkening with anger.

Emily was blushing and looked ashamed. "He'll pinch my butt, or start giving me a massage without asking, or just let his arm brush my boob," she explained.

"Why don't you go to the administrators?", Jacob asked. "Tell them what's going on!"

"Because there's no proof," Emily explained. "If I do that, he's not going to get kicked out of school, but for the rest of college I'll be the girl who accused a guy with no proof. So before I tell on him, I want to try handling it myself. And I thought if I hit him in his balls, he would learn his lesson."

Jacob nodded. "Well, OK," he said. "I still think you should report him, but it's always good to learn how to defend yourself against guys who get too handsy."

"So you'll teach me?", Emily asked, her face brightening into a huge smile. She ran around the table to her brother and threw her arms around his neck. "Jake, you're the best brother!"

"Come on," said Jake. "Let's go down to the basement."

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"OK," Jacob said. "First you need to learn about balls, and why they're so vulnerable. Let me know if this is too gross and you want to stop."

Emily shook her head. "Show me."

Jacob dropped his sweatpants to the floor, along with his underwear.. He stood in front of his little sister naked from the waist down. His family were far from nudists, but his sister had seen him without his clothes on plenty of times.

Emily giggled. "My bro's got a big dick," she bragged.

Jacob sighed. "It's not big, it's slightly above average," he said grumpily, pulling it to the side with a hand. "Besides, the dick is irrelevant to our lesson today. Today is all about BALLS." Emily laughed again.

Jacob sat down on a chair and spread his legs, holding his penis to the side with one hand so that his sister would have an unobstructed view of his testicles. She walked over and knelt down in front of him, examining them.

"See, they just hang outside of the body," Jacob explained. "There's no bone or muscle or anything. They're just two organs in a pouch."

"Wow," said Emily, examining her brother's balls closely. "They really are."

Jacob sighed. "OK now here's the gross part. If you're OK, try holding them in your hand."

Emily nodded. She reached out and took her brother's balls in one slender hand. Jacob felt his lower body clench with sudden fear, but he controlled it. He was safe in his sister's hands.

"Wow," Emily said, rolling the testicles around in her hand. "They're so soft. No wonder it hurts so much when they get whacked."

Jacob nodded. "When you have a guy by his balls, like now, you have his life in the palm of your hand. You can put him on the ground with pain. You can make him cry. You can even knock him out if you squeeze hard enough. And if you hold really tight on the part of the sack above the balls, there's no way he can pull out of your grip."

Emily's eyes were wide with wonder. "Wow, it's so easy to control a man," she said. "But what if he punches you while you're holding him?"

"He might," Jacob admitted. "But if you squeeze hard and fast, he probably won't have the strength for a strong punch. Usually when a guy's balls are being squeezed, he'll give up quick and start begging and surrendering."

Emily nodded. "But I'm not going to squeeze you, because I don't want to hurt you."

Jacob nodded, feeling suddenly relieved. "Thank you. I just wanted you to know how much power you can have if you get a guy by his balls."

"What does it feel like to get squeezed?", Emily asked.

"You feel it through your whole body," Jacob said, shuddering. "It's like someone's squeezing your stomach AND your balls. It's a very paralyzing pain, you can't even move really. You just want to curl up and do anything to save your balls. Anything."

"Wow," Emily said, wide-eyed. "That sounds horrible. Guys are so vulnerable."

"Yes we are," he agreed. "Maybe that's why we act so tough all the time. We have to distract women from the fact that they can destroy us any time they want."

He gently removed his sister's hand from his scrotum, and pulled up his sweatpants. "The problem is, guys are usually wearing pants," he explained. "So it can be hard to get your hand all the way around his balls."

"So what do I do?", Emily asked.

"Well, you can do a few things," Jacob said. "One thing you can do is try to grab his balls from underneath. Even if he dodges, it'll scare him. Here, try to grab my balls, like this." He showed her the correct motion.

"OK but I'm not going to squeeze you, OK?", said Emily. "I know," he said. "Just catch them in your hand."

Jacob came at Emily, reaching out as if to grab her. She swung her hand up and slapped him in the balls without grabbing them. Her brother doubled over and grunted, putting one hand over his crotch. He fought the urge to crumble to his knees, not wanting his sister to feel guilty about hurting him. And, to tell the truth, he also wanted to look tough in front of her.

"Oh my gosh, are you OK?", Emily asked.

He nodded, struggling to catch his breath. "That was good, but try for more catch and less slap."

He took a few moments to recover, and then they tried again. This time Emily missed completely. But on the third try, she managed to cup her hand around her brother's balls through his sweatpants.

"Got em!", Jacob shouted, even as he felt a slight jolt of pain from the squeeze. "Good job, Em!"

Emily grinned in triumph. "I'm learning!", she said proudly.

They practiced the move a few more times. Emily had great hand-eye coordination from playing tennis, and only once more did Jacob take a painful whack to his sack. His knees almost buckled but he managed to hold on, doubling over and breathing steadily until the pain receded.

"OK, now let's try some kicks and knees," Jacob said, panting.

"Wait, won't that hurt you really bad?", Emily asked, worried.

"It would, except I brought THIS!", Jacob explained. He grabbed a steel athletic cup from the shelf. "This will protect me really well. You don't have to worry about kicking me hard."

Emily nodded. Jacob stripped down again and strapped on the steel cup, making sure his sister saw that he was fully protected. Then he put his sweats back on, and faced her.

"You took a kickboxing class, right?" he asked.

"Yeah, just for a couple weeks though," Emily said.

"OK, well you know the basics of how to kick then," Jacob said. "Come on over and give me a solid knee right between the uprights."

Emily looked scared. "Are you sure I won't hurt you?" she asked. "I promised to never hurt your balls again, remember?"

Jacob smiled and nodded. "I'm safe, don't worry," he said. "Come on, show me what you got."

Emily stepped forward. Jacob put his arms on his sister's shoulders and started massaging them. "See, if he does this to you, you're in close, and you can easily give him the knee. Just make sure not to look down before you do it, so he doesn't see it coming."

Emily nodded. Without looking down, she gave her brother a light knee to his nuts. The hard steel cup hurt her knee a little bit. Jacob barely felt it at all.

"Ow," Emily said. "You weren't kidding."

"Harder," Jacob ordered. "It might hurt your knee a little but it's the only way to learn."

Emily stepped forward and drove her knee into Jacob's nuts with maximum force. This time he felt it, as the vibrations traveled through the cup. He winced and bent over. But Emily's knee was probably in as much pain. The two siblings stood there wincing and recovering from the impact.

"That was great," Jacob said, straightening back up. "Now let's do some kicks."

Emily backed up, and she practiced kicking her brother in his cup. He managed to twist away or back up or dodge most of the kicks, even without looking down to see where her foot was going. A few times he took painful blows to his thighs that made him wince. Twice she managed to nail him dead on, right up under the cup. He felt a small jolt of pain in his balls each time, along with pain in his pelvis from the rim of the cup. His balls were starting to ache, but he kept at it, for his sister's sake.

As for Emily, she was grinning more and more as she attacked her brother's groin. Once she got over the fear of hurting him, she felt the empowerment of being able to attack a man's vulnerable spot without holding back.

Then her foot hit Jacob on the side of his cup, between the cup and the thigh. Instead of his pelvis absorbing the blow, his balls took the force from the side. Pain exploded in his groin, and Jacob dropped to the carpeted floor like a ton of bricks. He immediately began to roll around, moaning in pain.

Emily's hands flew to her mouth in shock and horror. She had floored her brother, just like before. She ran over to the fallen Jacob and tried to help him, but just like when she had kicked him in the summer, she couldn't figure out what to do. So she just rubbed his back and head gently as he writhed.

"What happened?" she asked. "Did the cup come off?"

It was a minute before Jacob could catch his breath to answer. "I guess even a steel cup doesn't protect you 100%," he grunted.

"I'm so sorry," Emily said. "I didn't mean to hurt you."

"I know," he said. "It was my fault for getting cocky."

"Was that a pun?" Emily teased, ruffling her brother's hair.

Thanks to the cup's protection, Jacob was able to recover much more quickly this time than when his sister had kicked him in the summer. He rolled onto his knees, and then struggled unsteadily to his feet, where he took another minute or two to catch his breath.

Emily hugged him. "You sacrificed your balls for me, bro," she said.

"Luckily not," he breathed. "They're both still there in one piece. The cup helped a lot."

"You didn't cry this time," his sister pointed out, ruffling his hair. "You're getting tougher!"

"Let's not toughen me up any more," Jacob laughed, hugging his sister back.

"So am I ready to take down Bryce's balls?", Emily asked. "I feel like I could."

Jacob considered it. "Well, maybe also take a real self-defense class first," he said. "I don't know if I can take much more of this kind of practice. Here, let me get out of this cup."

He turned and pulled down his sweatpants, then stepped out of the cup, still moving gingerly from the pain. Just as he was naked from the waist down, his sister's hand suddenly shot out and grabbed him by his balls.

"Surprise!" she shouted.

Jacob almost jumped out of his skin. His hands instinctively flew down to grab Emily's slender wrist. She didn't squeeze, just held his balls lightly, closing her thumb and forefinger around the sack above the nuts themselves.

Jacob looked at his sister and saw a huge grin on her face.

"I got you by your balls, bro," she teased him.

"I noticed that," he said. "Please don't hurt them."

"Come on!", Emily laughed. "I'm not going to hurt them! I mean, on purpose. Sorry about before."

"It's OK," he said, laughing at the absurdity of his sister holding him by his balls. "I forgive you. It's not like I have a choice, right?"

Emily laughed. "That's right, you're my slave now."

"What do you want me to do, Mistress Emily?" Jacob asked, teasing her.

"First, admit you're the best brother in the world," she commanded.

"OK, I'm the best brother in the world," he agreed, smiling. "That was easy."

"Now admit you have a big dick," she teased him, looking down at the organ in question where it hung to the side of her hand.

Jacob rolled his eyes. "It's slightly above average," he protested.

Emily glowered at him, tightening her hand slightly around his balls.

"OK, OK, I have a big dick," Jacob said quickly.

"Good," Emily said. "I'm glad we agree. Now finally, apologize for letting me hurt your nuts."

"I'm sorry," he said sincerely. "It was my fault."

"OK," his sister said, releasing his balls. "Do you want a beer?"

"That sounds great," Jacob said. "I'll be up in a minute."

Emily bounced up the stairs. Once she was gone, Jacob sat down and gave himself a couple more minutes to recover. He had been acting tough in front of his sister, but the pain from her kick was still shooting through his abdomen. When it receded a bit more, he went up the stairs to the living room.

His little sister was waiting for him there with a beer. In addition, to his surprise, she was completely naked from head to toe. Her body was slender and very pale, and her cute face was blushing bright red.

"OK, what's this about?" Jacob said, narrowing his eyes.

"Well, I know how embarrassing it was for you to get kicked in the balls, and have me grab them, and stuff," Emily said. "So I thought it was fair for me to be embarrassed too. Plus you were naked before, so, you know. Now we're even."

"Go put some clothes on, doofus," Jacob laughed.

"Am I hot?", Emily asked, twirling around so he could see every angle. Jacob averted his eyes, embarrassed. "Do I look good naked?"

"If I say no, will you hit me in the balls?"

"No!", said Emily. "Well, OK, probably not."

"Then you're super duper hot. Hottest girl in the world. Now go put some clothes on and leave my poor balls alone."

Emily skipped off to her room, laughing, while Jacob sipped his beer and shook his head in amusement.

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It was 9 PM, and Jacob was studying in his room. His phone chimed, and he saw that his sister was asking to video chat. He flicked the green button and her face appeared. She was flushed and excited, with a huge grin on her face.

"I did it," she said. "I took down Bryce!"

"Hey, nice!!", he said, grinning. "How did you do it?"

"Well, I kinda cheated," Emily laughed. "We were in the same room alone, and he started putting his hands all over me. This time instead of pulling away, I pretended to go along with it, so I put my hand down his pants. He let me do it. You should have seen the look on his face when I grabbed him by the balls and started squeezing!"

"Oh wow," Jacob said. "Devious! What happened then?"

"Well, at first he yelled 'Bitch, get off me, bitch' and stuff like that. But I just kept squeezing him. Then he started to kind of whimper. He was trying to pull my hand off but he couldn't, just like you said. Then he started begging me to let him go, saying 'Please, I'm sorry', and stuff like that. So I said 'This is a lesson. Never touch me again, or next time I'll crush these balls to jelly and eat them on a piece of toast!' And I slapped him in the face while I said that."

Jacob couldn't help but laugh. "Amazing. Oh my God, Em, you're brutal!"

She smiled. "Then I let him go," she said. "He fell on the floor and started crying. I got up and left him there. I don't think he's going to give me any more trouble, do you?"

"I don't think so," Jacob agreed. "Congratulations, sis. I knew you could do it."

"I would just like to point out," his sister added, "that Bryce cried, while you didn't cry when I kicked you in the basement. Which means your balls are tougher than Bryce's."

Jacob privately thought that if she had grabbed and squeezed him instead of kicking him through a steel cup, he also would have cried. But he kept that opinion to himself. "Thanks, Em," he said. "And don't worry. My balls are fine."

"Thanks, bro," Emily said. "Thanks so much for everything."

​

*(The end)*