After spending a week with Zitao in China, Sehun is finally returning home. Time to start going back to university and his part-time baby sitting job. He sits at the departure hall and waits for his flight. There are two identical kids running around and playing. A week away without the kids from his work made Sehun realized how much he misses taking care of children. There's a lady sitting a few seats away from him also watching the kids as they play. The lady is really pretty with big eyes, gums showing when she smiles, Sehun feels his heart flip. Both the kids run towards her direction shouting, "Mommy!!!!" and said pretty lady stands with her arms wide open. That's when Sehun realizes that he doesn't stand a chance.

Just then the speakers go off asking for flight number KE2707 to board the plane. The lady stands up and holds the kids' hand. On the plane he sees that the two same kids are sitting in the seats next to his. He's about to go the seat when someone taps his back. It's the lady from earlier. "Hello, I'm Minseok. It seems that you have to seat with my kids for this flight. Let me apologize in advance just in case they cause you any trouble later." Sehun waves off the apology and ensures her that it's not a big deal as he takes his seat. "Luhan, be nice to the hyung next to you and take care of Wufan okay?" Minseok says before getting back to her seat.

Before take off the air stewardess checks all the passengers' seat belts. The kids next to Sehun have trouble with their seat belts so he offers to help. As they're about to take off Sehun sees that Luhan and Wufan are holding hands. It must be their first time flying, Sehun thinks. He takes both their hands in his to try and calm them down. He glances up to see Minseok smiling at him and mouthing a thank you. 20 minutes after take off, Sehun and Luhan have warmed up with each other, playing games on the in-flight entertainment set together. Wufan on the other hand starts to whine and cry. Minseok decides to comes over, and hugs Wufan to calm him down. Once Wufan has calmed down, Luhan suddenly decides to jump onto Sehun's lap.

"Kim Luhan, what are you doing?? Get back to your seat now!" Minseok scolds flustered and slightly embarrased.

"Ah it's fine, I don't mind really" Sehun ensures her.

"You're really good with kids," Minseok says. "I baby-sit part-time" Sehun replies and Minseok looks surprised.

Throughout the flight Sehun entertains Luhan while Minseok coos Wufan. When the air-stewardess came by with the snack cart, Minseok had bought the kids snacks and a drink for Sehun.

"You have really cute kids ma'am, and they look just like you sir" The air stewardess had commented. After the flight they exchange numbers.

A week later Sehun is busy studying for an upcoming assessment when he hears his phone ring. It's a text from Minseok asking if Sehun is free to baby-sit on short notice, sehun replies almost instantly. The door bell rings and he greets the kids and Minseok smiles at him.

"Behave yourselves kids!" Minseok warns, "and thank you so much for doing this. I'll be back at 10pm."

When Minseok leaves, Sehun lets the kids watch television as he prepares dinner. The door bell rings again and Sehun opens the door to a very obnoxious older brother of his. The kids in the living room, curious goes to the door.

"Jongdae ahjussi?" Luhan asks. "Oh!!! Luhan what are you doing here??" Jongdae asked equally surprised.

"Mommy left us here and went to work." Luhan answers as Jongde ruffles his hair.

Sehun looks between Jongdae and Luhan. The kids continue watching pororo as Jongdae helps Sehun in the kitchen. "Hyung, how do you know the kids?" Sehun asks Jongdae. "Ah I know their mother, we used to go to college together." Inwardly, Sehun wants to probe further but decides against it.

The kids come over often and Sehun sometimes goes over to their house. On weekends, Sehun brings the kids out for ice-cream or to the park when Minseok has work. Everywhere he goes with Luhan and Wufan, he hears that the twins look a lot like him. He also realizes that Luhan and Wufan resemble him a lot in different ways. Luhan is playful and childish while Wufan is quiet and chic. Like Sehun in two versions, as he likes to think to himself. He and Minseok have also became closer over time. Sehun feels like he's falling for Minseok every time he sees her.

Minseok invites Sehun out for coffee one day. Sehun asks Jongdae to help baby-sit Luhan and Wufan for the day. Minseok comes over and leaves the kids with Jongdae. They go to a cafe nearby Sehun's house.

"I actually need your help, the kids' birthdays are tomorrow and I need aid in preparing for a celebration." Minseok says as they wait for their coffee.

So this is how Minseok and Sehun find themselves shopping at the children's section of the mall planning a birthday party and shopping for presents. They look at clothes, toys and party decorations. The woman working at the party store commented that they look like a really sweet married couple. They both blush and look away.

When Jongdae visits the next time. Sehun asks about Minseok's husband. "Minseok doesn't have a husband. She got pregnant from artificial insemination, something about being lonely." Sehun almost falls to the floor. He has had his donated before.

"Wouldn't it be funny if I was Minseok's donor?" he says but quickly dismisses the fact. They probably resemble Sehun since they hang out together almost every day. He tells Jongdae to forget what he said but his brother has other ideas. Jongdae decides to visit the bank the next day. He gets Sehun's file and sends it to Minseok by mail.

Minseok wanted to stop Sehun from coming that morning but she has an important meeting to attend, and Sehun is already on his way. Minseok left the file in her study and rushes to work once Sehun arrived. Sehun thinks that Minseok must be running late.

"Sehun hyung I want to draw." Wufan says tugging on Sehun's pants.

He's being led into the study room by Wufan to get the paper. From the corner of his eye, Sehun spots an oddly familiar bright blue file thrown carelessly on the desk. Out of curiosity, he reaches for the file and realizes that it contains his contract with the bank. Shocked, he drops the folder as Minseok runs into the room to retrieve the file. Minseok looks at Sehun, then the file, then back at Sehun.

Minseok avoids Sehun for the next few weeks and Sehun tries to keep his distance. Sehun really misses the kids. And now that he knows they are actually his, he feels more affectionate towards them. And he misses Minseok even more. He wants to call Minseok and tell her that everything will be alright and that he really likes her. Like like her. Sehun calls and messages Minseok but she doesn't answer. Sehun decides to 'coincidentally' bump into the kids at the park near Minseok's house. Luhan and Wufan runs up to hug him.

"Hyung we missed you! Where did you go? Do you not like us anymore? Mommy got us a new baby-sitter. We don't like her. We want you." Sehun wants to hug the kids. His kid. Minseok comes from behind Sehun but turns at her heels once she sees Sehun's back.

"Mommy! Look who's here!" Luhan shouts. Sehun turns around but Minseok is walking away faster.

Sehun runs after her and pulls her back by the arm. "I think we need to talk."

They're at the cafe near the playground. They sit opposite each other avoiding eye contact.

"I heard you got another baby-sitter." Sehun starts, "are you not going to let me see them again?"

Minseok looks confused. "Why? You're not their father."

Sehun looks dumbfounded this time, "But I am??? They were conceived with my "

Minseok laughs almost bitterly, "So what do you want to-" Sehun cuts Minseok mid-sentence. "Let's get Married." Minseok looks bewildered. She stands up and leaves the cafe. Sehun thinks he might have acted a little too rashly.

Sehun comes up to Minseok's doorstep. A jewelry box in one hand and a bouquet in another. "Will you, Kim Minseok, marry me?"

Luhan and Wufan's birthday is in a week. Sehun is frantic mess in the delivery room as Minseok screams in pain. Sehun is about to faint but he hears a baby's cry. The nurse passes a newborn into his hold and Minseok continues pushing, screaming louder. Sehun hears another baby's cry. It's over now. He stares at the twins in both his and Minseok's hold. They look beautiful and he wonders how Minseok managed to do this alone when Luhan and Wufan were born. He approaches his wife and kisses her forehead. Luhan and Wufan come running into the room as Sehun carries the newborns to let Luhan and Wufan look at their new brothers. They've decided to name the new set of twins Jongin and Junmyeon. Sehun thinks that donating to the bank was the best decision he has ever made.