The first time they're interrupted, it's only been a day or two since they plucked Leonard from the time stream, where he'd been swept in the wake of the Oculus explosion and held in a sort of suspended animation. Gideon, with a tone of surprise, has pronounced him fit and well, and although Amaya and Nate are still looking at him out of the corners of their eyes, most everyone agrees that he's back on the team.
Sara's escorted him to his new room and, trying to remain captain-like and purposeful, is telling him about the new system of kitchen duty on the ship—a practical detail that keeps getting derailed by the look in Leonard's eyes. Her businesslike lecture eventually grows slower and slower, his responses vaguer and vaguer, until they're both just standing there staring at each other.
He moves slowly enough, eyes on hers, that there's no doubt what his plan is, plenty of time for her to respond with another retort and depart, leaving no doubt about her feelings.
She doesn't. She meets direct blue eyes, and licks her lips, and then she's being pulled into his arms and kissed. By her crook. Who's one hell of a thief, after all.
It's not much more than a warm touch of lips, the slightly awkward bump of noses, the taste of mint and the briefest promise of something deeper and more satisfying, when Gideon breaks in with an apologetic reminder that she needs Sara's input to set the coordinates to their next destination. They break apart with regret, but smiles on both their faces, and both of them know that they'll pick this up again later.
Whenever "later" comes.