Sure thing! Imagine these two scenes taking place a few chapters apart -
The four of us sat in the corridor, stained in soot and blood. But that wasn’t the worst of it. The horror of what had just happened was nothing in comparison to the closed infirmary door and the muffled sound of Marion’s voice shouting orders.
“Everything’s going to be all right,” said Evan, loud enough for all of us to hear though his gaze was fixed on Zachariah.
“How could it be? What if…”
“Don’t say it,” said Anastasia. “Don’t you freaking dare–”
“That’s enough,” I managed. The last thing Genevieve would want was the four of us fighting while she was in that room, fighting for her life.
Anastasia tossed her hair back and stood, marching down the hall. “Waiting here is useless. Come and get me if anything changes.” Then she was gone. I turned to Evan just in time to see him reaching for Zachariah’s hand, but the moment their hands touched Zachariah pulled away.
“Just, not now,” he said, and it was obvious I wasn’t meant to hear it. I turned my face away.
“This is a suicide mission,” said Anastasia. “Graham, you’re going to get us all killed…”
“If we don’t go after her now, then when?” I said, turning to face her. “Zach, what do you–” I turned to face him, eyes widening in surprise. “Well, holy…”
“Oh boy,” said Anastasia as she turned too. Zachariah had both his hands twined through Evan’s hair, and the two were oblivious to the fact that they weren’t alone as they leaned in to kiss.
“It’s about damned time,” I said, rolling my eyes.
“Hey, guys. Suicide mission. Imminent death.” Anastasia turned toward them, hands fisted at her hips. “Why don’t you save the hooking up for after we’ve convinced Graham she’s being stupid about this.”
Since this little example is written in first person, you can imagine the narrator wouldn’t be there for the private moments between the couple in the story. But there’s enough information here to see that Zach - who in an earlier tense moment pulled away - has gotten over his discomfort with being open about a relationship with Evan enough to be the instigator of some PDA in a later tense moment.
It happens off-screen, but you - the reader - can imagine that there’s a story happening there. With a few more details scattered throughout the narrative you’d be able to get a pretty good idea of this subplot, even if the narrator isn’t there for most of it.