The first time he called, it was a welcome surprise. While Ed had been under his command, he'd really only called to give the bare minimum of an update, run off a string of curses, and hang up before Mustang could throw anything back. That was the routine they'd had for nearly three years, and it was always strangely comforting. Mustang was alway able to tell how well the brothers were doing just by the amount of insults. The more fire, the better.
The calm and almost cautious voice on the other end of the line was a drastic change from a few months ago, but also not entirely alien. Roy had caught glimpses of it- the real Edward Elric, buried deep beneath desperate determination to fix what had gone wrong- but that vulnerability had never been visible for long. While the Fullmetal Alchemist had been headstrong, impulsive, and hot tempered, the man left behind was quiet and good natured, and still had a temper if need be. It suited him well.
They chatted easily about the past couple months, about how Al was adjusting to life with a body again and Roy's plans to rebuild Ishbal. There was the typical flare up when he told Ed about using the philosophers stone to regain his eyesight, but it was clear there was no resentment because of that decision.
"And by the way," Ed said after nearly a half hour of conversation, "there is one more I'm supposed to tell you." There was a pause, and Ed seemed to be reconsidering what he'd been about to say. When he finally spoke, the words were rushed. "Al says congrats on your promotion to General. I say I'm dreading the day you become Fuhrer."
It was a year before Edward called him again. It also happened to be the day Mustang was leaving Central to visit Ishbal, and everyone around him seemed to be determined to make him late. As much as he would have liked to spend a half hour or more catching up with Ed, he simply didn't have the time or the patience.
"I have a train to catch in half an hour. Is this important?"
There was no pause on the other end of the line- even Ed knew not to go silent when on the phone with Mustang -but there was still a stunned disappointment in his voice as he spoke. "I guess it's not."
"I can call you later when I get the chance-"
"Don't bother, I won't be near a phone for a couple days."
This time there was silence, and Roy couldn't quite stop himself from asking if everything was alright. It seemed to be enough to break Ed out of his strange mood.
"Of course I'm alright! I'm just going to Rush Valley with Winry! I wouldn't be stupid enough to call you if I wasn't!"
By the third time Edward called, Roy was beginning to notice a pattern, although the particular significance of it eluded him. Unlike Alphonse, who called with clockwork regularity every other month, and had even visited central a couple times, Ed would only call to talk to Roy once, around the middle of the year.
The phone rang late in the day, late enough that most people would have been asleep. However 'most people' didn't involve alchemists when research was involved. That, and the fact that Alphonse had mentioned Ed traveling to Creta during his most recent visit to Central. Dead of night in Amestris was only late evening for the western area. Roy had intentionally chosen that particular week to stay up unreasonably late, on the off chance that Ed didn't take time changes into account.
Perhaps he'd even deliberately ignored them.
"Oh, I almost forgot," Ed said after 45 minutes of easy conversation. "You find yourself a wife yet?"
"Since when do you care about that?!" Mustang growled. "And you're an adult now- how about I start asking you the same question?"
The laugh that rang through the line was so purely happy that it was difficult for Roy to believe the sound belonged to the same man who'd seemingly carried the world on his shoulders just two years ago.
"You'd only have to ask it once. I'll make sure Winry sends you an invitation."
The fourth call was very brief as Edward called him in a complete state of panic from the hospital in East City.
"She even kicked me out of the room! Said I wasn't being helpful! But how am I supposed to do that when I don't even know how to be a father!"
"Are you telling me the Fullmetal Alchemist is capable of saving an entire country, but not raising a child? How disappointing."
"I'm serious! Winry's in there right now having our baby and I have no idea what to do. Not now, not in three years, not even the next 18! How am I supposed to be a father if I barely even had one myself! The best I had wasn't even-"
"You'll do great, Edward," Mustang said, although a little at a loss himself. The closest he'd come to raising children had been babysitting Elicia and the Elric brothers themselves, which hardly qualified him to give advice. "If anyone can do this, you can."
A third voice broke into the conversation; although faint, it was still distinctly Al. "Ed! Get back in there, you'll miss it!"
"Okay!" Edward took a deep breath to steady himself, and the next time he spoke he sounded appropriately proud. "I'm going to be a father."
There was a click as Ed hung up, and Mustang couldn't help but grin, a particular one he hadn't worn since Hughes had called him in a similar state of panic nearly ten years prior. There was something special about someone becoming a parent from the first time.
However, there was still that one ever elusive detail that Roy couldn't quite place. He didn't have to glance at the calendar to know it was the third Sunday in June.
If it was something in particular he was missing, Hawkeye would be able to figure it out far faster than he could. He dialed her number with well practiced fingers and only had to wait until the second ring for her to pick up.
"Hawkeye?"
"Yes sir."
"Is there any particular holiday on the third Sunday in June that I'm forgetting? This is the fourth year in a row that Edward's called me on this day."
Hawkeye never missed a beat. "Only Father's Day, sir."
"Oh." Roy thought about that for a moment, finally staring idly at the calendar and flipping a pen between his fingers. Likely just an actual coincidence then. After all, it wasn't as if-
The pen dropped back to the counter with a clatter.
"Oh."
The next time that particular Sunday rolled around, Roy didn't need to wait for his phone to ring, choosing to make the call for himself. Winry eventually answered, but passed the phone to Ed at Mustang's request.
"What's the occasion? Yuriy's birthday isn't until tomorrow."
"I know. I just wanted to keep up with the yearly tradition."
Ed made a noise like he'd choked on something for a second. "... What yearly tradition?!"
"Third Sunday in June."
"I don't know what you're talking about."
"No? In that case, tell Yuriy happy birthday tomorrow. And I'll tell you happy Father's Day for him, since he can't. You've done a great job."
There was a long pause, and then, "Same to you."