I mean, goodness, the slow tension starting to build between Abraxas and Severus is quite delicious! Also, not only does Lucius deserve a smack for not telling Abraxas that Severus likes blokes, but didn't Lucius even say Severus preferred women? BOO. Makes me wonder what eye Lucius turns towards Severus.
I love the way you've written Poppy here, that she's an old friend of the family and communicates with Abraxas in code. I've never read Poppy as anything but uncomplicatedly Light, so this was a wonderful, fascinating, deep touch. And Poppy's comment about the taking of the "Lord" title as being pretentious made me chuckle. Indeed, Poppy, indeed!
And the conflict Abraxas feels, and his high moral standard (waiting until Severus is done with school before taking him into his bed for sexual reasons), and the care that he shows in wanting to relieve the young man of both his nightmares and his uncertainty...not to mention (as alisanne already has) Abraxas's reluctance to introduce Severus to Lord Voldemort.