Save Me From This Darkness
Peter/Claire. Focuses on how guilty Peter and Claire feel about their feelings for one another, particularly concerning Nathan.
These lyrics just fit their twisted relationship so well, especially from Peter's POV. So, listen carefully!
Canon Paire, so if that squicks you out, move along! OR, just pretend this is a nice look at a completely appropriate uncle/niece relationship OR you can even pretend that this is AU and the two are not related at all.
Whichever way you choose to look at it, I DO NOT want to see any "ew, gross!" comments. Again, if you don't like Paire, don't watch!