When Prue and Piper are standing in line for the bathroom at P3 and talking about Dan and Jack, camera shots alternate between Piper fingering the necklace and the necklace just laying around Piper's neck.
Piper tells Dan that her secret has nothing to do with him, then less than a minute later she contradicts herself and says it has to do with him and her, and what she'd like them to become.