It was on the day of Halloween where everyone is getting ready to dress up for Halloween. In Starship Entertainment dorm, Cravity members are getting ready to dress up for Halloween. Among of them, Park Serim was dress up as a demon so he can take his secret girlfriend out on the date since none of the managers knew about it. Serim doesn't know what Jisung is going to wear but hoping that she would dress up as an angel.

"Serim, any idea when your girl is coming?" Allen asked.

"No, but hopefully soon," Serim replied.

Serim went to the living room to sit on the couch while thinking of what costume that Jisung will be wearing. Then heard the door open as he looked at the door to see Jisung in her angel outfit. Serim smirked softly as he was right about Jisung being an angel. Jisung walked into the dorm and look for Serim. She couldn't find him but see the demon on the couch since she couldn't tell who was behind the demon outfit.

'Who is this cute demon?' Jisung thought.

Jisung walked to the couch while Serim watched Jisung walking toward him. Before Jisung could ask who he is, Serim grabs Jisung's hand and pulled her to his lap. Jisung yelped and blushed softly as she tried to get up.

"Hello, my cute little angel," Serim whispered in Jisung's ear.

"S-Serim-Oppa!" Jisung exclaimed.

Serim chuckled softly and kiss on her cheek. Jisung blushed and hugs Serim.

"You looked so cute in demon outfit that I didn't recognize you," Jisung said.

"Thanks but you looked so adorable as an angel," Serim said.

Jisung smiled softly and got up from sitting on Serim's lap. Serim got up and take Jisung's hand as they walked out of the dorm. They were walking away from the dorm and the managers so they don't get in trouble or caught. When they are very far from the dorm, they were walking holding their hands tightly while heading out to the park.

"Serim, why did you decide to dress as a demon?" Jisung asked.

"Because I want to since I am your demon while you are my angel," Serim said.

Jisung blushed at the comment. When they got to the park and went to sit at one of the benches away from many people as they want to be alone. Jisung lay her head on Serim's shoulder. Serim smiled softly and kiss her forehead.

"So much has changed since we met each other," Jisung murmured.

"It has. We were very lucky to keep our relationship in secret that the managers don't know about it," Serim said.

Jisung nodded. Jisung and Serim were looking at each other before watching the water fountain. They stay in the same spot for several hours. Before they headed out, Serim went to kiss on Jisung's lips. Jisung blushed softly and slowly kiss back.

"I love you, Jisung," Serim said.

"I love you too, Serim," Jisung said.

"Someday we can date freely without having the managers yell at us," Serim said.

"Yeah," Jisung murmured.

Jisung and Serim got up from sitting on the bench and heading back to the Starship Entertainment dorm to have the party. When they arrived at the dorm, their friends are dressed in their costumes like wizards or werewolves. Serim and Jisung went to join them to have fun and tell some scary stories but not too scary since not all of them want to sleep having a nightmare. When they decided to play some games like roleplay so Serim as the demon decided to chase Jisung as the angel. Jisung laughed as she is running from Serim who is trying to catch her.

"Can't catch me, cute demon," Jisung called while running.

"Oh, I will, little angel," Serim said chasing Jisung.

Cravity members were laughing while watching their leader chasing his secret girlfriend. When Serim finally caught Jisung, he held her in his arms not letting her go. Jisung squeals and tries to get free but ends up snuggled in Serim's arms. Woobin brought the food out and put it on the coffee table so everyone can eat. Serim and Jisung sit next to each other as others see that they haven't been apart that long. When the party is over, Serim walked Jisung out to the door. Jisung stopped Serim from going to the door.

"Serim, can I stay with you tonight?" Jisung asked.

"Sure," Serim said.

So, they walked to Serim's room. When they got there, Jisung went to the bathroom to change into her PJs while Serim changed as soon as Jisung is in the bathroom. After both lovers changed and went to Serim's bed. Jisung looked at Serim and lay down. Serim smiled softly and kiss Jisung's forehead.

"Did you have a good time?" Serim asked.

"Yes, I did. I am happy that you invited me to come here for fun," Jisung replied.

"Good night, my cute little angel," Serim said.

"Good night, demon boy," Jisung said before falling asleep. 

Serim smiled softly before falling asleep holding Jisung close to him.

Jisung belongs to beyondsevenexokidsx as I made this oneshot for her