Draco-the-godson-of-Snape
Just because Narcissa Malfoy says Snape knows Lucius well and is Draco's favorite teacher does not mean he's Draco's godfather. Let's take Draco first. Since Draco got to Hogwarts Snape has established a precedent of favoring Slytherins. To what extent this is an automatic House-favoring thing versus a deliberate deep-cover spying technique is not established, but it's a useful way of establishing bona fides.
On top of this, Snape has an interest in cultivating Draco, because it keeps him in the Teflon, as Draco will hardly scurry off to Lucius whining about Big Bad Snape if he thinks Snape will turn a blind eye to anything he does.
Lucius isn't an idiot; he's a pureblood, and he knows there's no such pureblood family named Snape. He is not, I think, going to let some scruffy, greasy half-blood be godfather to his child, who is practically royalty due to Narcissa being a Black. There's a difference between being friends due to a shared contempt for Muggleborns (although it can be argued that Snape only professes this to stay in good with other Slytherins), and being such bosom buddies (like the Marauders) that one would be willing to let the other be godfather to a child. It is hinted in canon that being a godfather invests someone with legal responsibilities in the event that the father isn't alive, and while Snape may be half-a-Prince, and no matter how benevolently disposed Narcissa is towards him (I suspect half of that in HBP was her desperation, though - gee, am I cynical or what for a Ravenclaw? ;) ), I think Lucius would have rather named another pureblood godfather, if at all.
Personally, I think Severus Snape is generally out for himself. He's a Slytherin, after all. To this extent I think he realized that sticking close to Lucius could help his career, but I think one of the things that would sour Snape on his friendship (if we can call it that) with Malfoy is the fact that the latter bought his way out of Azkaban with an Imperius defence, while Snape, not having that kind of money, needed Albus Dumbledore to save his bacon from Azkaban.
Honor among thieves, my arse.
I'd make the case, therefore, that while Severus makes a point of keeping Draco thinking he's a good Slytherin and a great Professor, he does so purely for the purposes of manipulating Lucius Malfoy. I would bet anything that if he hadn't had to make the Unbreakable Vow, he wouldn't have lifted a finger to help Draco in the boy's task. Why would he, when at least some of his loyalty is to Albus Dumbledore, and hindering Draco by refusing assistance (on any grounds he can dream up - e.g. he's too busy, he has to help Slughorn brew the Wolfsbane, whatever...) could have well been as effective as actively slapping Draco down.
So, there's my cliche-bashing for you. :)
On top of this, Snape has an interest in cultivating Draco, because it keeps him in the Teflon, as Draco will hardly scurry off to Lucius whining about Big Bad Snape if he thinks Snape will turn a blind eye to anything he does.
Lucius isn't an idiot; he's a pureblood, and he knows there's no such pureblood family named Snape. He is not, I think, going to let some scruffy, greasy half-blood be godfather to his child, who is practically royalty due to Narcissa being a Black. There's a difference between being friends due to a shared contempt for Muggleborns (although it can be argued that Snape only professes this to stay in good with other Slytherins), and being such bosom buddies (like the Marauders) that one would be willing to let the other be godfather to a child. It is hinted in canon that being a godfather invests someone with legal responsibilities in the event that the father isn't alive, and while Snape may be half-a-Prince, and no matter how benevolently disposed Narcissa is towards him (I suspect half of that in HBP was her desperation, though - gee, am I cynical or what for a Ravenclaw? ;) ), I think Lucius would have rather named another pureblood godfather, if at all.
Personally, I think Severus Snape is generally out for himself. He's a Slytherin, after all. To this extent I think he realized that sticking close to Lucius could help his career, but I think one of the things that would sour Snape on his friendship (if we can call it that) with Malfoy is the fact that the latter bought his way out of Azkaban with an Imperius defence, while Snape, not having that kind of money, needed Albus Dumbledore to save his bacon from Azkaban.
Honor among thieves, my arse.
I'd make the case, therefore, that while Severus makes a point of keeping Draco thinking he's a good Slytherin and a great Professor, he does so purely for the purposes of manipulating Lucius Malfoy. I would bet anything that if he hadn't had to make the Unbreakable Vow, he wouldn't have lifted a finger to help Draco in the boy's task. Why would he, when at least some of his loyalty is to Albus Dumbledore, and hindering Draco by refusing assistance (on any grounds he can dream up - e.g. he's too busy, he has to help Slughorn brew the Wolfsbane, whatever...) could have well been as effective as actively slapping Draco down.
So, there's my cliche-bashing for you. :)