what you see as a guilty look, i see as real emotion. She says he's done enough, to take the amulet off - but he says he's got to finish the job and she accepts that - knows what its like to have to make a big sacrifice for the greater good - she's done it herself. The difference here is that Spike is saying, you don't have to do it this time, i will. I won't make you run a sword through me, i won't cause you to jump off a tower, i will take your burden because i love you. So she says i love you to him - not because she has to but because she feels it. he is in her heart, she loves him but more importantly, she is able to say it to someone, a man, other than Angel for the first time since they broke up because the whole point of season seven has been teaching her to love again after shutting off her heart at the end of season three/beginning of season four. Love is about actions not words. the words are nice but actions tell the whole story, the real story. Buffy and Spike's season seven relationship in season seven is remarkable - it's the building of love in action - each and every episode.