If you haven't already read A Brother's Curse by DarkenedSunlight ... you need to. That story inspired me so much to write similar ones.
Disclaimer: I obviously do not own Fullmetal Alchemist Brotherhood
It was raining & Colonel Roy Mustang was extremely tired. He had gone to bed at 2:00 a.m. because he was up all night working on paperwork that had to be done or else Hawkeye would shoot him when he got to work in the morning and he had finally just gotten home at 6:00. It was currently 7:15 and he was sitting on the couch reading a book while also wondering what he might do for the rest of the night. A few minutes later he heard a knock on the door, he rose to his feet wondering who it could possibly be? He sure was surprised when he opened the door to find Edward Elric on his doorstep looking extremely afraid and horrible in general.
"Fullmetal? What are you doing here?"
"Hey-y Colonel Bastard."
"Where's Al? I've hardly seen the two of you apart" Right after Roy asked that Edward coughed harshly and almost fell over.
"E-Ed? Edward?! Whats wrong!?" With Ed about to collapse Roy grabbed him and dragged him into the house to lay him down on the couch. When he settled Ed down, he opened his eyes and Roy could see so much hurt and pain in them, it broke his heart to see the boy he loved like a son like this. Edward closed his eyes a second later again and Roy bent down to lightly kiss his forehead. As Ed fell asleep Roy saw his face relax and calm down which in turn calmed him down. He left Ed on the couch and went into the kitchen to make himself a cup of tea for the rest of the evening seeing as it was about 7:30. Twenty minutes, later he heard a knock on the door again. He turned around, exasperated with everyone coming to his house today. When he opened the door he sure was surprised to see Alphonse and Hohenheim standing there.
"Al, can I do something for you?"
"Sorry Colonel to interrupt your evening, but I wanted to tell you Ed ran away from Dad and I and we couldn't find him anywhere." While Al was speaking Hohenheim just stood there looking into the Colonel's home.
"Why did he run away? That seems unusual, even for him." the Colonel said deciding to play along.
"He was being sensitive and he refused to listen to us at all!" Hohenheim interrupted just as Al was about to speak.
"While that does kind of sound like him." Of course while Roy said this he was smirking. "I'll look for him tomorrow and if I still can't find him I will get the others to help."
"Thanks Colonel. We will be leaving tonight to travel across the desert and go to Xing and after that, other countries."
"Oh really? And Ed is not coming, even if you can't find him right now you won't wait for him?"
"No."
"Alright. I will make sure to look for him, Good luck on your trip." After that Roy just about slamed the door on them. He leaned against the door shaking in rage. How dare that bastard Hohenheim and surprisingly even Al not care that much about Ed. How could Hohenheim even say he was Edwards father, he definitely didn't deserve that title.
"R-Roy?" Hearing his name be spoken the Colonel looked up in surprise to see Ed standing there looking like a little kid who just woke up from a nap. Roy looked at the clock wondering what time it was to see it was almost 8:20, about half an hour passed.
"Ed. Shouldn't you be resting?"
"Yeah...but I heard you talking to someone when I woke up. I-It was Al and Hohenheim wasn't it."
"...Yes, will you tell me what happened?"
"...okay."
"How about we go sit on the couch so you can at least rest a little and not waste your energy standing up." As Roy said that they moved to go to the couch & Ed started coughing but he didn't notice the concerned looks Roy was sending him. After a few more steps Ed started to fall to the ground when he felt strong warm arms catch him and then pick him up so he was being held bridal style. As Roy sat down on the couch with Edward still in his arms he noticed Ed was leaning into his chest. Roy made no motion of letting Ed out of his arms so Ed just leaned in closer to Roy's warm chest like a little kid would do to their Dad.
"C-can I tell you tomorrow? Sorry, i'm just really tired...if you don't mind."
"Sure Ed. I agree with you, its getting late and it has been a long day."
Roy stood up with Ed still in his arms and started walking down the hallway. At the second door on the left Roy stopped and put Ed down then opened the door. "You can stay in this room tonight, my room is right next door."
With that Roy said goodnight and then walked to his room where he quickly got changed and fell asleep.
4 hours later
Roy woke up to the sound of someone crying, startled as to think no one else was in his house but he realized a minute later that Ed was here. Hurrying out of his room, down the hall and into the room Ed was staying in, he saw him crying curled up into a ball in the middle of the bed. He then sighed, Ed was too young to have to go through nightmares like this after all he has been through. Roy walked towards Edward and then tried to wake him up, and about 5 minutes later did Ed finally wake up. Instead of saying anything to Ed Roy just hugged him and held Ed close. A few days later they became Father and Son officially.