Once, long ago, long before Mystery Spot, I read a groundhog-day fic for SPN. Now, because of Mystery Spot, Google cannot help me find it, and of course the link through which I think I originally found it is dead.

It was Sam and Dean trapped in a timeloop, both of them, and having no luck getting out, and it was mostly about the effect this had on their psyches. Sam started getting really depressed, and refusing to get out of bed, so Dean stopped trying to escape and focused on getting Sam up every day, collecting some things to make the empty house they were staying in homey and fun, finding things for Sam to do. Eventually it turned into Wincest, but not for the sake of cheering anyone up, more as another effect of getting stuck in the timeloop. They get out when they're partway through convincing every person in town to join them in a threesome, I believe, which was pretty funny, especially since the fic was very serious otherwise.

I've been going crazy trying to find this for a couple of weeks. It was a really wonderful fic, I miss it. Thank you for any help you can give!