I agree with Post #3. I think that Snape's loyalties lie only with Lily. Yes, he does obey Dumbledore, but I do not think that it is out of a complete trust in Dumbledore. Instead, it is out of the idea that only Dumbledore could continue to connect him to his love for Lily. I think that everything that Snape has done in these books has come out of his love for Lily (and his hatred of James).
I would argue that his loyalty, in the very end, lay with Lily, Harry's mother. He certainly was willing to go along with what Dumbledore asked him, partially out of loyalty to him and perhaps a desire to protect Lily's offspring, namely Harry. But it becomes quite clear that his deep and lasting love for Lily has haunted him his whole life and still drives him to make decisions that he knows would lead to enormous difficulty for him.
The distinction is really a small one, however, as he clearly is quite loyal to Albus and willing to follow the advice of Dumbledor when it comes to making sure that the right things happen that will lead to the triumph of good over evil.
Severous Snape's true loyalties lie in the death of Lily Potter. Snape dedicated the rest of his like in redeeming himself because he caused the death of the woman he loved. Therefore, he began working for Dumbledore, and protected Lily's only son, Harry Potter, from Voldemort's hands.
definetly @post 3 is saying right thing.......cuz snape protect harry just because he love lily potter n there is absultly no arguement ab0ut his loyality cuz he j0ined lord v0ldemort that means he knew one day he would die but t0 safe his love s0n he took all risk.......one thing which made snape my fav0urite character is that he love harry m0re than ayn1 else c0uld d0 but he never b0asted that he l0ve him instead he quitely gave SACRIFICE f0r him.....this als0 sh0ws his true loyalities.....h0pe this will help
His true loyalities lie with Albus Dumbledore. Dumbledore was one of the few that trusted him and his love for Lily Potter. Snape was friends with Lily Potter since they were kids and grew love for her over time. When she died, Snape swore to Dumbledore to protect Harry from harm. Also, Snape killing Dumbledore was an act of loyalty as well, as Dumbledore told Snape to do it. Hope this helps. :)