You spot him busying himself in the back of his father's wand shop, covered in sawdust, actively sawing a piece of wood; presumably for a new wand. He seems rather focused. His father is manning the front desk, where you stand, and is giving you a polite smile, waiting for you to show interest in their wares.

That's when you catch his eye. He looks up momentarily, glancing up to check for customers, when his eyes land on you. With just one glance, he looks smitten with you.