You talked to Himchan about Yongguk babysitting and he did vouch for him. In fact, Himchan even went so far as to suggest using Yongguk to babysit quite often. Then the next week, there was a schedule mishap as Catalina's shift got switched around and your normal babysitter wasn't available. So you hesitantly called Yongguk but he only eagerly agreed to babysit.
When that day arrived, you let him in your apartment and eyed the backpack he was carrying. "I'm not making you skip class am I?"
"Oh, no. No. It's just for studying." he quickly reassured you. "Class is tomorrow."
"Oh, okay." you said. Then you picked up Minjun, hugging him and kissing him before passing him to Yongguk. "I don't have to say anything do I?"
He chuckled. "I'll take care of him. Promise."
"Thank you." you said and then held Minjun's hand for a moment. Then with some reluctance still, you left him with Yongguk and went to work.

When you came home, you found Yongguk sitting on the couch and feeding Minjun. "Hey." you said.
"Hey." he replied and indicated your son. "He's just fine. No need to panic."
You blushed a little and nodded. "Yeah. Sorry."
"It's fine." he said and then shifted to burp the baby.
You went to change out of your work clothes real quick and when you came back out, Yongguk was stuffing his stuff back in his bag. "Well, I should... um... go. If you need me again though..." He trailed off and gave you a sheepish smile.
You looked at him and bit your lip as he turned to leave. "Wait."
He turned back and gave you a questioning look.
"Do you want to stay for dinner?"
He raised his eyebrows in surprise and stuttered out incoherent words. "Uh... No It's... I don't.. want to impose. I.."
"Yongguk." you said, cutting him off. "I... I really appreciate you watching him. It's a lot of help." You took a deep breath. "And I'd like to be friends with you. Just friends." you added for emphasis.
He stared at you for a moment before swallowing and his lips. "I'd... I'd really.. like.. that. Friends."
"Okay then." you said and then Minjun started fussing. You went to pick him up but Yongguk grabbed him instead.
"I got him." he told you.
"Thanks." you said. "What do like to eat?"
"Anything." he quickly said and then blushed slightly "I mean... I... I'm not... picky. So just..."
"Okay." you said and went in to the kitchen. You set about making a meal for three that way Catalina had some when she came home. Then while it cooked, you went back out to the living room.
You watched Yongguk with Minjun and couldn't help but smile. "You really do know what you're doing."
"Yeah." he told you as he rocked the baby. "I meant what I said before."
"Sorry." you offered. "I just..."
"It's okay." he quickly assured you. "You're just... a good mother."
You blushed slightly at the compliment and went to sit on the couch. "So... how's school going?"
"Good." he replied and sat down as well.
"And overseas?"
"It was a lot of fun."
Then the two of you sat in silence for a little while before you let out an awkward chuckle. "Sorry. Guess I really don't know anything about you."
"No." he quietly agreed. "You don't." Then he chewed on his lip for a moment before looking at you. "I'm majoring in chemistry. When I graduate, I want to work in a lab. In my free time I like to read and I... Well... I make music too."
You raised your eyebrows and nodded. "Wow. That all sounds nice. Maybe I can listen to your music some time?"
"Really?" he questioned and stared at you in surprise.
You nodded. "Really."
Then a shy smile formed on his face. "O-okay." he stuttered.
The two of you talked for a while, getting to know him, and then Catalina came home. You went in the kitchen to set the table and she followed you. You noticed the look she was giving you as she smiled.
"What?" you asked. "He's been a lot of help and I just..."
She kissed the side of your head. "You're growing up."

The three of you had a pleasant dinner and chatted. Then Catalina offered the suggestion to just have Yongguk be the babysitter since the one you had was getting unreliable.
"Oh no." you hurriedly said and turned to Yongguk. "I couldn't ask that."
"I want to." he said.
You shook your head. "But your classes."
"It's fine." he told you. "It won't interfere and I... I really... want to."
"Very enthusiastic of you." Catalina commented and winked at you.
Yongguk blushed hard and shyly looked down. You gave her a look and she gave you one right back. Then you looked over at Yongguk. He really was good with Minjun and if he was available...
"Are you sure it won't interfere?" you asked him.
He quickly looked up at you with a hopeful look in his eyes. "No, no. It won't. I promise."
You looked at him thoughtfully and then nodded. "Alright then. Thank you."

Yongguk became your babysitter and it worked out really well as you became more comfortable leaving Minjun with him. Then when you tried to pay him, he adamantly refused.
"Yongguk." you lightly chided.
"No." he firmly said and forced the money back in your hand. "I'm not going to take your money."
"But.."
"He needs more formula. And buy the one for sensitive stomachs. I think the formula he's on now is too harsh for him. And he's starting to grow out of the smaller size clothes so buy him some new ones to grow in to." he told you.
You blinked at him in surprise and he blushed a little.
"I... I just... really want... to do want I can to help." he mumbled.
You swallowed and then gave him a grateful smile. "Thank you."
"That's what friends are for, right?" he asked with a shy smile on his face.
"Right. At least let me make you dinner though." you offered.
He quickly shook his head and stammered but you gave him a look. "Friends?" you questioned.
He blushed again and then nodded. "Alright. Thanks."