Based on a radio interview Xiumin did. He said he shares a dorm with Chen and Lay and that he likes it because they're quiet.  

Minseok had woken up promptly at 5 like he normally would, no matter what schedules they had, he would still wake up at 5. At times it was a nuisance but he had long since grown used to it. He went about his normal routine; getting fresh, having a healthy breakfast and excising.

The clock read 6:30 and Minseok thought he should begin making breakfast for his wonderful dormmates. Yixing had just come back after 3 weeks in China and today's schedules all began later on in the afternoon, so Yixing and Jongdae naturally took advantage of that. But they're good dormmates so they hardly made any noise and Minseok thought he'd repay this kindness by making them breakfast.

At 7:03, Minseok knocked once on the door of Yixing and Jongdae's room. A few seconds later, a very tired and groggy Yixing answered the door.

"Minseok hyung?" he asked in a raspy voice.

Minseok winced at the sound of his voice. "I made breakfast." He noticed a gag ball lying on the floor next to the bed. "And brought things to soothe sore throats."

Yixing gave him a dimpled smile and kissed his cheek. "Thanks hyung."

Yixing jumped back into bed with Jongdae and spooned the boy. Minseok watched as Jongdae curled into Yixing as he came into the room. He laid the breakfast tray on the table before grabbing a chair and bringing it closer to the bed.

"Thanks for not making any noise." he said once he had taken a seat.

Yixing giggled quietly and kissed Jongdae's throat making the younger boy stir and whimper in his sleep. "With Jongdae's vocals and me being away for so long, we didn't want to take any risks and disturb you."

Minseok smiled fondly at them and stoked their hair. "Best dormmates a man could've asked for." He looked at the two of them cuddling and sighed sadly before shaking all nostalgic thoughts from his head. "Take the Advil first. I made chicken soup and peppermint and liquorice root tea, it's best to drink them while they're still hot so you better wake up Jongdae soon. There's a bottle of saltwater, gargle it after breakfast. You know where the lozenges and painkillers are?" Yixing nodded. "Good and drink plenty of water. You can go back to sleep after you have breakfast and I'll wake you up before our afternoon schedule."

"You're so thorough hyung, no wonder you're EXO's biggest trend." Yixing teased.

Minseok reached over and hit his arm. "Don't say that! I'm only thorough because I don't want to give SM any reasons to complain about us." He got up and placed the tray on the chair he was sitting on. "Eat."

He then turned around and left their room.

A few minutes later, Jongdae hoarsely called out; "Thanks hyung!"

Minseok cringed but replied cheerfully; "You're welcome." 

I seriously want to make an OT3 fic with Xiuchenlay but my writing skills are abominable.