From the time Soren officially joined Ike's family, they'd been inseparable despite their many differences. Ike was bold, outgoing and idolized his dad, Soren was quiet and brooding and didn't care much for company. But somehow they'd hit it off and Ike had never been happier to have someone in his life. Soren watched him train, taught him how to read and write, they helped Oscar with the household chores until Mist was old enough to do a better job. They bathed together, slept in the same room, huddled under the blankets during a storm.
They never fought, even though most boys picked each other for target practice as they grew up, even best friends. But again, despite their differences they never had any reason to fight. They didn't always agree, but Soren was always happy to see things from Ike's side and value his opinions as much as he didn't value most other people's. Most saw this as strange, but no one ever called attention to it. It was just the way Soren was.
When the boys were in their late teens, Soren went to study with another mercenary group. Neither was too happy about it, but Ike let him go in good faith. It was beneficial to Soren's studies, and Soren promised to write home every day. When he returned early to bring news of the war, Ike couldn't help but being selfishly relieved-not for the war, of course, but to have Soren back with them. With him.
Soren had always been there for him. Anytime he couldn't sleep or had a nightmare about not being able to remember his mother, Soren would crawl into bed with him and hold his hand. When Shinon tried to make him feel like dead weight because he wasn't an actual mercenary yet, Soren would put the man in his place with a few words. The night Father died, Soren stayed up with him and let him vent his fears and worries until he could finally sleep. Every battle, Soren was at his side, ready to back him up with a well-placed spell or heal whatever wounds Mist's Physic staff couldn't reach.
The night he finally faced the Black Knight, Soren and Mist were by his side, Mist knocking out any reinforcements who tried to stop Ike and Soren healing any wounds he received. Ike won, of course, but their victory was saddled with fleeing the collapsing castle Nados and Nasir's confession.
Their first kiss came that night, once they were finally alone in their tent and Ike was reminded once again of how lucky he was to have Soren in his life. Everything fell into place in those few seconds, and nothing needed to be said.
Love, to them, wasn't a sudden realization. It wasn't a secret, or a forbidden yearning. It was the natural next step in a relationship as close as theirs, and Ike welcomed it. There's only one place in the world for me to be, Ike...and that's by your side.
They became lovers shortly after the war ended, another natural step. It was slow and hesitant at first, with Ike worrying their size difference could end with him accidentally hurting Soren and Soren still insecure and self-conscious about...well, everything. But gentle touches and nervous kisses gave way to reassuring gazes and eager embraces. Soren tried to pretend it didn't hurt when Ike thrust into him but Ike held himself still until he was sure Soren would be okay.
It wasn't perfect, not by a long shot. Ike came too quickly, settling for finishing Soren off with his hand and Soren apologizing for Ike not lasting longer.
"Don't worry," Ike said once they'd settled under the covers. "We'll have plenty more chances to figure this out."
"Plenty more...so this is permanent, then." Soren's smiles were so rare that they were all the more special when they actually surfaced, and they were always for Ike.
"I want it to be," he said. "Do you?"
Soren's response was to nestle further into Ike's arms, and Ike sighed happily. Tomorrow they'd wake up and eat breakfast with the rest of the mercenaries like any other day. Somehow the fact that they'd just had sex for the first time and would have sex many more times in the future didn't seem like a world-shattering change. A big thing, yes, but to Ike it was just one more step in the relationship they'd always had.