I'm looking for a fic I read a month or two back. The story was sort of based on the song House of the Rising Sun, that might even the the fic title as well. Sam and Dean ended up at this hotel where guests were forced into different sins by this lady witch. She wanted Sam and Dean to sleep together. I remember one line where Dean kissed Sam and said something like, 'this is the sin she wants'. I think Dean had been having feelings for Sam before the whole ordeal started and Sam said he had too, but Dean was convinced it was all because of the lady witch. I hope that's enough to go on.

ETA: Found by allyoops