"Well I definitely owe you one." He leaned back on his elbows, his hair falling elegantly down over one of his eyes. He couldn't keep himself from giving the girl the once over. She was pretty, he had to admit, in a 'hot librarian hiding behind her glasses' way.
"Of course! I remember you now." He'd seen her with Lily and Alice, though he couldn't remember her name. As he looked at her, he realized something: this wasn't the first time they'd met. Her shy demeanor and the innocent look in her eyes reminded him of a chance meeting back in their first year. They'd ran right into each other in the common room, and he'd grabbed her to keep her from falling. The memory brought a smile to his face.
"So, how can I repay you for helping me out? After all, I always pay my debts."