A/N
This is a one shot from just after Ulaz met the Paladins and protected them.

It is a normal, quiet evening in the Castle. The rest of the team have already headed to bed, but Keith and Shiro are restless. The recent encounter with Ulaz... it reopened old wounds. They set up a blanket and pillow nest in a large room, surrounded by windows, allowing them to watch the stars. Keith lies on his back, resting his head on Shiro's stomach, watching the stars in awe, bright smile on his face. Shiro smiles, petting Keith's hair, humming a small lullaby his own mother used to sing to him. It's peaceful and in war, moments like these are cherished.

"Shiro?" Keith speaks up, quiet, as if he's afraid to break the silence.

"Yes, Yurak?" Shiro asks, never any hint of annoyance or anger in his tone.

"Have you ever been in love? What's it like?" Keith wonders aloud, open curiosity in his tone.

"What's brought this on?" Shiro asks, keeping his tone warm.

"I just... Momma loved Papa... she said it a lot, but it's... I don't know... I love Momma and I love you and I love Red and I love Matt and I love Hunk and Pidge and Coran and Lance and I think I was learning to love Ulaz and I loved Allura, but..."

"It's called being in love, little kit," Shiro smiles, moving a lock of hair behind Keith's ear, before wondering aloud, "You've always been sensitive to emotions, even if you don't understand all of them."

"People feel different," Keith answers.

Shiro doesn't respond, having never understood what Keith means when he says that. Instead, he thinks back to Keith's question and takes a moment to reminisce, collecting his thoughts.

"I've been in love many times, but there was one person I wanted to spend my life with," Shiro answers, breaking the comfortable silence, "Like how your Momma and Papa wanted to be together forever."

Keith turns onto his front, arms dangling over Shiro's legs, and looks up at Shiro, enraptured, "What happened?"

"I went on a mission he didn't want me to go on and we had a big argument," Shiro explains, "I don't regret it though, because I got to meet my kit."

Keith pushes himself up so he's kneeling in front of Shiro, "What's his name? What's he like?"

"You're Takashi Shirogane, the best pilot in our class. I'll take that title eventually. My name's Adam. Adam W-"

"Hey! Adam! We're leaving!"

"I'll see you around."

"Adam. He... he's loyal to a fault, but extremely stubborn and overprotective," Shiro smiles warmly, slight sadness dimming it.

"He sounds like you," Keith laughs.

"Oh, really?" Shiro laughs, "That must be why we got along so well, but got into fights a lot. He was always more logical."

"Why did you love him, if you fought so much?" Keith cocks his head to the side.

"If you truly love someone, you work past that sort of thing. It makes your bond grow stronger."

"I..." Keith hesitates and looks away from Shiro, "I knew someone. He was nice to me... Momma didn't like him..." Keith takes a deep breath, "They didn't know each other long, but they didn't like each other... he still visited a lot and Momma never told him to leave..."

Shiro smiles and pulls Keith against his chest, "They put their differences aside for someone they loved. It's similar, but not quite the same..." Shiro looks out at the stars, "Adam... we would argue, often over stupid things, like putting a colander in the wrong cupboard, but sometimes, we argued over important things... being a pilot at the Garrison was dangerous and sometimes we had to do stupid things that meant we got hurt."

"You didn't like it when he got hurt and he didn't like it when you got hurt?"

"Exactly..." Shiro kisses the top of Keith's head and raises his metal arm for Keith to look at and fiddle with, "Remember what I told you about my arm? Why getting this arm was good for me?"

Keith's face falls slightly as he plays with the fingers, "You were sick. The kind of sick that doesn't get better."

"Adam didn't want me to go on the mission, because he considered it too big of a risk with my illness."

"Then why did you go?" Keith asks, looking behind himself at Shiro.

"Being a pilot at the Garrison... I loved flying and setting new records and reaching new heights that humans had never reached before. It was a part of me and made me happy... without it..." Shiro looks away.

"You wouldn't be happy and life would lose meaning," Keith finishes the sentence patting Shiro on the head, like Shiro does to comfort him.

Shiro smiles at Keith and continues, "Adam knew that, but he'd rather know I was safe and alive than happy... he gave me an ultimatum..."

Keith frowns, "That's not nice."

Shiro shakes his head, "You're right. He told me that, if I left, he might not be there when I came back. He made me chose between the two things that brought me the most joy in the world, back then."

"You didn't like that."

"No, I didn't," Shiro gives Keith a sad smile, "I'll always love Adam, but I'm still bitter and angry that he made me make that choice," Shiro's smile becomes brighter, "A choice I don't regret."

They settle back into silence, admiring the silence, holding each other in their little nest.

"Shiro?"

"Hmm."

"I love you."

Shiro chuckles, "I love you too, little kit."