I hope I'm not crazy here, but I could swear I read a series of stories quite some time ago in which Sam got kinda moody at some point (I think it might have had to do with the anniversary of Jess' death or something). I believe Dean maybe got frustrated or worried about Sam and ended up putting Sam over his lap? From there, Dean realized that Sam needed the ... structure (for lack of a better word) of a dom/sub thing. Sam really wanted it, too. I honestly can't remember if they were in a sexual relationship before this revelation. There were a series of stories.  I think it covered a variety of kinks at different spots in the series (only a couple of which I can remember with enough certainty to tag). Does anyone have any clue what I'm talking about here? Thanks in advance for any help anyone can give.

FOUND! Link in comments :) Thank you ayane42