Biting the inside of her cheek lightly to suppress a grin at his delicate ways, she looked down at the ground when he nudged her in return, recalling the last time they'd fallen into aggressively bumping one another. Or the time after that.

"After Hogwarts?" The question made her smile all the wider, reaching out finally to take his arm instead of just nudging it over and over. "Well, I suppose I'll travel the world being brilliant won't I?" Lily looked over at him and tilted her head with playful inquisitiveness. "Shall I write you letters, Sirius?"