He was always taught that it's rude to stare, but he can't help it tonight. She's in the best armchair by the fire, her long legs dangling over the arm, bare feet twitching to the beat of some old song played softly on the wireless. One hand is holding a book, inches from her bent head; the other alternates between stroking her cat, curled up on her lap, and brushing away the curtain of dark hair that escapes from behind her ear every so often. Each time she moves it, he catches a glimpse of pale skin and an expression of concentration, eyes moving rapidly over the pages of her book. In the firelight, her colours are brighter, warmer, her hair gleaming with threads of crimson and copper and gold, her skin tinged with a rosy incandescence. There's a tranquillity, a serenity to her at odds with the girl who snorts when she laughs. When she laughs at his jokes.
The curtain of hair falls again, and as she moves her hand to push it back, her head moves a fraction; she pauses, then looks over her shoulder, directly into his eyes.
He freezes, realising the intensity of his stare and knowing that it would be futile to feign anything, to quickly return to his work. Instead, he raises his eyebrows and gives her a small smile.
She smiles back, then raises her hand and makes a gesture that his mother would consider far ruder than staring.
I'm considering a series of James + Lily drabbles throughout sixth year, the year that doesn't get covered that much! So ... this could be turned into something more, if the interest is there. :)