Snape and Lucius Malfoy

[lea.macleod at gmx.net]

No: HPFGUIDX 17314

I´ve raised this before on the "Draco and Snape" thread since it´s 
been bothering me for a while: The relationship between Snape and 
Lucius Malfoy.

 We know *suspiciously* little about that so far. I don´t think 
 there´s a single scene in any of the books where Snape and Malfoy 
sen. actually meet face to face and talk to each other.

I just came across this in GoF last night:

In the "parting of the ways" chapter, Harry tells Fudge the names of 
the DE who were present at Voldemort´s rebirth to make him believe it 
really happened, and when he names Lucius Malfoy,

"Snape made a sudden movement. But as Harry looked at him, his eyes 
flew back to Fudge." (paraphrase).

That´s another fantastic hint giving wings to our thoughts, isn´t it?
What are your theories?

Was Snape surprised that Lucius Malfoy was present there?
Does Lucius know Snape was Dumbledore´s spy? Does he trust him at all? 
Does he see Snape as a secret ally or as an enemy? Is he happy with 
Draco being "tutored" by Snape in Slytherin or does he mind?