Hee, thank you! I didn't know we were a genre! But yeah, we both like comfortable and warm and pleasure! And Hermione. And pants monsters. *veg*
I think Lucius is utterly opportunistic -- doesn't really WANT to have to sacrifice Snape for Draco, or Narcissa for Draco, or Draco for himself, but, you know, whatever keeps him alive in the end makes it all negotiable. Whereas Narcissa, I think, is a bit more ferocious where Draco is concerned; she'd rather kill off Severus than Lucius to protect Draco, but if she has to kill off both of them, so be it.