It doesn't happen at a Christmas or New Years Eve party. They aren't at a bar with too many empty bottles on the table between them. Valentine's Day passed months ago with out incident. There's no particularly difficult case that makes either of them desperate for immediate comfort. Jack doesn't stand at his side, silently reminding him that he's motherless now.
It doesn't happen the way it would on a sitcom; there's no romantic comedy cliche to fall back on.
What happens is this.
Aaron's rifling through his briefcase when Garcia slips through the closing elevator doors, Lynch right on her heels. Her makeup looks like it was slapped on during a bumpy car ride and she looks just a little too skewed from the tangled ringlets of her hair to the obviously hastily tied bows on her heels to have taken even a fraction of the time on her appearance that she normally does. Lynch always looks like he just stepped out of a wind machine, so his improperly buttoned shirt and crooked tie aren't worth a second look, but the grin stretched wide across his face is even goofier than usual. Aaron doesn't have to be a profiler to know they both rolled out of bed at the last possible moment this morning and what it was that kept them there so long.
Garcia smiles at him, her expression a hundred times brighter than the elevator's florescent light--which isn't flickering for once--and chirps a, "Morning, bossman," and Aaron offers a small half smile of his own, because there's no way he can do anything else. Lynch gets a nod that isn't entirely curt as an afterthought.
Aaron turns back to his briefcase, because he would swear he put the file he's looking for in there, while Garcia and Lynch lean into each other, their voices soft, but animated as they talk about something that goes completely over his head. He glances up just in time to catch the fuzzy reflection of them kissing in the polished stainless steel elevator doors, and something kicks low and hard in his stomach. That makes him pause, his fingers sandwiched between carefully organized papers and his brow furrowed in a frown, but it isn't until the doors ding open and the pair of them exit together in front of him, Lynch's hand at the small of Garcia's back and Garcia laughing happily up at him, when he feels the second, more insistent kick and a lump in his throat like he just missed a step on a staircase and came down on nothing but air that he gets it.
Oh, he thinks faintly, his ability to breathe abandoning him at the realization. Well. Fuck.