She watches him watching the foot traffic on the sidewalk, considering his profile, the stubborn set of his chin. As she taps a finger against her water glass something catches his attention outside, and he smiles softly and exhales with a satisfied puff. It is at that moment that the feeling clicks into place just under her ribcage.
What she would like to do is reach across the table and take him by his slender wrist. She would like to bring his attention back to her, to the spot on her left cheek that he always looks at rather than look her in the eye, and tell him, "When I heard you sigh right now, I knew that I could love you. If that was what we were doing. If it was even possible." And then she would like to stand up, fold her napkin neatly, and leave. Because knowing that she could hurts more than knowing that she's not allowed, and until just a moment ago she wasn't sure that was possible.
Instead, she echoes his sigh and grasps herself by either elbow. She is rubbed raw by all of the things that she wants and cannot have, weighted down with knowing that faith and deservedness count for little in anything. She closes her eyes and watches the warm red of the sunlight through her eyelids, and after a second the feeling passes. When he turns from the window to look at her, she hardly hurts at all.