Could, Would, Should Have
Sometimes Tom watches Harry.
He's the perfect Gryffindor, Tom often thinks with a grimace of distaste and a moment of regret.
If things had gone only a bit differently, he could have been the perfect Slytherin.
He wears too much muggle clothing, Tom often thinks with a sneer of disgust and a smidgen of longing.
If things had gone only a bit differently, they would have both been wearing muggle clothing, and still living in an orphanage.
He smiles a lot, Tom often thinks with a frown and a unsettling bump in his chest.
If things had gone only a bit differently, they wouldn't be in different houses, with different friends and different lives, and that smile would be for him.
Shame, that, Tom thinks as he turns back and smiles as happily as he can at Draco, who grins right back, with pink dusted cheeks and continues talking, ignorant of what has just happened.
If things had gone only a bit differently, Tom should have not felt gnawing emptiness in his chest where his heart was supposed to be.