Krystal clenched her fists as she watched her sister and Kai, one of the members from SM's newest boy group, cuddling and giggling backstage. Her eyes darkened as she stepped out of her hiding place.

"Unnie." her voice was cold and sharp. The couple turned to her. Jessica quickly pulled herself out of Kai's embrace and ran over to Krystal. "We should get on the stage now, "Hope" is playing already." she said and grabbed Krystal's hand.

As they passed by Kai, he slipped his hand into Jessica's and gave it a squeeze. "I'll see you on stage." he whispered into her ears, and Jessica unconsciously blushed. She nodded and pulled Krystal away. Krystal glared at Kai, but was shocked when Kai winked back at her. *He winked at me! What does that mean?* Krystal had always thought Kai was pretty good-looking and was interested in him, but then she found out that he was dating her sister. When she saw them behaving so intimately backstage just now, she secretly felt like killing Kai. She was really surprised at her own thoughts, because she didn't knew she liked Kai that much.

"He likes me! Yeah, that must be it!" she mumbled to herself. Jessica heard her mumbling and looked at her. "What are you saying?" she asked, as she thought that Krystal was talking to her. Krystal glared at Jessica for abit and completely ignored her. Jessica raised her eyebrows in amusement. "Yah, what's wrong with you again? Walk down with me during my verse okay?" she asked and held Krystal's hand tighter. Krystal softened, but only for a short while. She rolled her eyes and harshly broke off their interlaced hands.

"Walk yourself." she said coldly and ran off to where the other f(x) members were. Sunny, who was beside Jessica, looked shocked at Krystal's behaviour because everyone knew how close the two sisters were usually.

"Sica ah, what's wrong?" she asked, looking at Jessica's hurt and confused face. Jessica shrugged and looked down at her feet. *I gotta talk to her later.*

**

"Hey you guys, walk with Jessica down the stage during her verse, okay?" Jonghyun whispered to Chanyeol and Suho. The two guys nodded eagerly with bright smiles on their faces. "Of course!" they agreed and hopped over to where Jessica was. Jessica smiled gratefully at Jonghyun who gave her a small squeeze on her shoulder. "I saw that, I'll talk to Soojung." he said softly and went to the back.

Jessica sighed and started singing her parts. Suho and Chanyeol walked with her, and then the rest of EXO followed. As she was someone who never stay mad or depressed for long, she smiled at the bunch of EXO guys who were excitedly skipping around her.

She met eyes with Suho who was sticking close beside her. "Thanks." she merely said and wrapped an arm around his shoulder. The rest of the EXO members got excited and started making funny sounds. Jessica giggled and shook her head. "You guys."

Suho looked at Jessica and smiled. *I saw that too, noona. And it hurts so much to see you masking your unhappiness beneath a smile.*

**

Krystal was excited when she got to stand beside the EXO guys. She craned her neck to see where Kai is and smiled when she finally spotted him. She sneakily (and casually) tried to make her way beside him, but unfortunately she was being ed by Victoria and a few SJ members.

"Damn it." she cursed under her breath. She suddenly caught Jessica at the far side, chatting happily with Suho. She frowned at the sight and decided to tattle tell on her. She finally got the opportunity when everyone started to leave their areas to walk back to the far end middle stage. Kai was walking pass her and she grabbed his arms.

"My unnie is cheating on you." she said and pointed to where Suho and Jessica was. Kai looked over and was pissed off when he saw Suho trying his best to entertain Jessica, and they were both giggling about something.

"That hyung. I knew he was just faking it when he said that he was really happy for me and noona. And how could that do this to me." he muttered under his breath. Krystal snapped her head towards Kai when he heard what he called his sister.

"You. What did you just called my sister?" she hissed, glaring menacingly at him. Kai rolled his eyes at her and gave a face. "." he simply said and walked off. Krystal was clenching her fists so tightly that she was sure that her knuckles were blue already. She turned to the large audience cheering and decided she should not make a fuss now.

When the whole of SMTOWN had said their goodbyes to the audience, everyone started making their way backstage. Once backstage, Kai immediately pulled Jessica into an empty pantry room.

"What were you doing with him just now?" he hissed, his hand grabbed Jessica's arm tightly. Jessica winced in pain and tried to struggle out of his grip. "Jongin ah, it hurts." she whispered. Kai ignored her and held on even tighter.

"I saw you and Suho hyung just now. What the hell were you two doing? Ah, so Suho hyung finally confessed to you? How could you do this to me?!" he almost screamed. Jessica scrunched up her face in confusion. "What are you talking about?!" her voice was raised, something she rarely did.

"I love you so much, but this is what you are doing to me. I hate to be made a fool." he growled. At that moment, the pantry door was pulled open, and there stood Krystal. Jessica looked at her, shocked. "Soojung ah, you-"

"What are you two doing?!" she shouted. She had misunderstood the situation. She thought that Kai and Jessica were making out in the pantry.

"Soojung, I-" Jessica tried to explain, but Krystal stepped back away from her.

"Did you know what he called you just now?! He called you a ! I can't believe that I was actually about to give him a black eye for you when you two are making out here!"

Jessica glared at Kai.

"Stop putting words into my mouth! I knew that you liked me from the start, and now that I'm with your sister, you are jealous right?" he scoffed and draped his arm around Jessica's shoulders. "Give it up, I will never like you."

Krystal slapped him. "Then why did you wink at me just now?!" she was close to crying.

"!" he cursed and send a slap back to Krystal's face. "You were the one who was thinking too much!-" Before he could say anymore, a smack was thrown across his own face. The two looked at Jessica in shock. Jessica pushed Kai away roughly. "I'm breaking up with you. Get out of my sight now." she growled.

Kai threw his hands up into the air. "What?! Why?! I thought you loved me!"

Jessica went over to Krystal and wrapped her arms around her shoulders tightly. "Anyone who dares to hurt my sister will be my eternal enemy. You better get the out now or I'm repeating that action again." she hissed. Kai wanted to say more, but he knew that Jessica wasn't kidding. Giving one last glare to them, he stomped out. After he left, Jessica turned to her sister and worriedly checked her face. "Did that hurt?! I should have known better than to go out with an immature boy. Damn it I'm not finished with that bastard." she cursed as she Krystal's red cheek.

Krystal suddenly started sobbing. "I'm sorry unnie." she apologized while crying. Jessica frowned and wiped her tears. "For what? That bastard's not worth it. But, I'm sorry too. I didn't know that you liked him too."

Krystal shook her head. "I just realized that I wasn't jealous of you, unnie. I.. I was jealous of him. Jealous that he got to spend more time with you. Jealous that you might not want me anymore. I just didn't realized that and even tried to broke you two up." she confessed.

Jessica softened and her sister's cheek. "Yeah silly. But thanks to you, we got to see his true colours right?" she comforted her sister and pulled her into an embrace. *You stupid kid, you are more important than any guy to me.*

Her eyes then caught someone standing outside the door. *Joonmyeon?*

Suho bowed apologetically without approaching the pair. "I'm really sorry." he mouthed. Jessica grinned as she remembered what Kai said just now. "For liking me?" she mouthed back. Suho's eyes widened. *OH.MY.GOD. HOW DID SHE KNOW?!* He blushed and quickly ran away, leaving Jessica secretly chuckling to herself.

A/N: Uhm sorry if this turned out weird. >:) I love how Jessica and Krystal are so affectionate towards each other! I wished I had a sister too! A little susica at the end haha!