This was something I'd always wondered about- how well Al's soul and body "got along" after so many years apart. Post-series, so spoilers for that. Enjoy!
Having his body and soul reunited was by far the best day of Alphonse's life. He was eternally grateful for everything his brother had done, but there were days where, well…
There were days he wanted to punch his body and soul.
Sure, getting the hang of eating and sleeping had been disorienting, and physical therapy had been grueling, but that wasn't the reason he found himself brimming with pent-up frustration.
His body and soul may have been reunited, but they had a tendency to argue. A lot.
And it was over the most inane things. The two had been separated for so long that apparently they'd gotten used to functioning independently. They forgot that the other part had limitations and would bicker back and forth, leaving Al standing half-dazed in the middle of the room as he got caught up in the internal dispute. Sometimes it was over what he was going to wear or what book he was going to read. Other times it would happen in the middle of a sparring match with Ed- his soul would have a plan that his body (no longer tireless armor) simply couldn't do and his body would dig in its heels and refuse. And then Ed would beat him cleanly, give him a good ribbing, and then go bother Winry over the new ankle joint prototype she was testing on him.
Al was sure that in a couple years he would find the split between his body and soul fascinating, but right now he wanted to pull out his hair. If there had been a way to put his soul and body in time-out, he was certain he would have done it. (The only thing he could think of was to kick his body back to the Gate or stuff his soul in the toaster, but he wasn't that desperate. Yet.)
And today, Al realized, was going to be no different. Today the topic of dispute was pie.
"Have a slice!" his soul declared as Al eyed the pie on the counter. He'd come in for some water, but had been staring down the dessert for a good five minutes.
"You had one last night!" his body snapped. "You keep eating it and you'll make yourself sick. Rotten teeth, vomiting, dia-"
"Shut up! I went five years without any pie, I think I deserve it."
"Oh, just you? I went five years without any, too!"
"Then you should be on my side!"
"You're not the one who has to hug the toilet bowl! We did that last week, I'm not in a hurry to try it again!"
"Listen, the pie has apples in it. They're healthy, let's eat it."
"No!"
The squabble went silent for a minute, and Al dared to hope that the two of them were done and he could get on with his day. But apparently, it was not to be. Al barely had time to turn away from the offending pie and leave the room before his soul dragged the argument back up.
"I should get final say since I was the one who did all the work."
"Excuse me?" Al had no idea his body could sound so offended.
"Yeah, you heard me! I was the one out there fighting Scar and the Homunculi. And where were you? Sitting around on your butt like a bum!"
"HOW DARE YOU!" For a brief, terrifying second, Al was sure he was about to find out whether a body could forcibly eject the soul by sheer anger alone.
"…Al?"
Al felt himself jump a foot in the air at the voice. He turned hastily, both his soul and body dropping the argument as Ed stared at him in confusion. "Oh, hey, Brother. I thought you were out at the Henderson farm today."
Ed slid further into the kitchen. "Yeah, finished early." He raised an eyebrow. "What're you doing?"
"Just, uh," Al shuffled awkwardly. "Deciding if I wanted some pie."
"Al, you deserve all the pie you want," Ed said, reaching around his brother for the knife. "You want one or two slices?"
Al could practically hear the gears in Ed's head shifting to Doting Older Brother mode so he reached out and snagged Ed's wrist before he could start cutting into the pie. "No, look, I know I can have it whenever, but I don't want to make myself sick again."
His brother deflated a little, then perked up. "We can split a piece, how's that?"
That, Al decided, was a good a plan as any. He agreed and decided not to say anything when Ed gave him the slightly larger half of the slice.
"I win!" Al's soul crowed smugly as Al sat down at the table across from his brother.
"You did not!" his body shot back. "This isn't over!"
Al stifled a sigh with a mouthful of pie.