1. Dean/Castiel. It was an AU where Cas is a mute drifter taken in by Bobby and Ellen. He hasn't spoken since his twin brother, Jimmy, died. There is a scene in the fic where Cas sits on the roof outside his window at Bobby & Ellen's. I think Dean climbs out there and sits with him. There's another scene where Dean finds a newspaper clipping in Cas' stuff about the death of his brother. - Dream As If You'll Live Forever by commodoresexual.

2. Sam/Dean. All I can remember about it is that Sam and Dean pick up an OC in a bar and take him back to their motel room so that the OC can watch them have sex. Sam tops and at the end, Dean tells the OC that Sam is his younger brother. - Libido by poisontaster

Thanks!

ETA: Added more details to #1.