“If she means so much to you,” said Dumbledore, “surely Lord Voldemort will spare her? Could you not ask for mercy for the mother, in exchange for the son?”
“I have – I have asked him – “
“You disgust me,” said Dumbledore, and Harry had never heard so much contempt in his voice. Snape seemed to shrink a little. “You do not care, then, about the deaths of her husband and child? They can die, as long as you have what you want?”
Snape said nothing, but merely looked up at Dumbledore.
“Hide them all, then,” he croaked. “Keep her – them – safe. Please.”
-Harry Potter and the Deathly Hallows, chapter 33
This is the best insight we’re ever given into the character and motivations of Severus Snape as a person, and the picture it paints is not a good one.
Snape has no regard whatsoever for Lily’s happiness. As long as she’s alive it doesn’t matter to Snape what she goes through—because Snape doesn’t like Lily’s husband, he doesn’t mind helping murder James. I get the strong impression that Snape would see a suffering, grieving widow whose son he sold to Voldemort as exactly the same little girl he used to stalk when they were kids together. It would be mission accomplished, because she didn’t die, although he’d probably avoid her because of all the crying.
Snape doesn’t get that the object of his infatuation has a life that matters to her and a family she’d die to protect. He does not value Lily’s feelings at all, and never has.
Lily may be the most important object of affection in his life, but she’s still that: an object, onto which he projects whatever strong feelings motivate him to do other than massacre the impure.
And oh, how narcissistic his regrets are once she dies! He doesn’t grieve Lily, he uses the idea of her to punish himself. He doesn’t honor her memory, he tortures her surviving child for daring to be alive when she’s dead. And yet, somehow, he does good things despite himself.
I loved the eventual revelation that this complete monster has a secret hidden soft spot, but he lost any chance at my admiration the first time he humiliated Neville in class for the pleasure of watching the kid fall apart.
Am I moved by Snape’s secret hidden manpain? Not even close, because it’s just as self-serving and rotten as the rest of him. I admire the fact that somehow he did the right thing despite himself, staying true to his slimy character all the while, and it somehow all worked out to the good.
Dumbledore saw how empty Snape’s soul was, how mean and small his character. He understood exactly what made Snape tick: the raging self-interest and neverending desire to punish himself forever that he thought of as “love”. He saw how to use it and accepted Snape for what he was.
That’s why I think he trusted him.
Unsurprisingly, Luka speaks truth.
Ooh ooh and I have more, I’m still re-reading. Here’s a scene from after Dumbledore’s death, when Snape is in Number 12 Grimmauld Place:
Snape took the page bearing Lily’s signature and her love, and tucked it inside his robes. Then, he ripped in two the photograph he was also holding, so that he kept the part from which Lily laughed, throwing the portion showing James and Harry back onto the floor, under the chest of drawers.
Fifteen years after her death he has not changed at all.
What a goddamn creep.

