I am searching for a fic that I read a while back (I think it was on spn_hardcore that I had actually found it). It was a wincest where John held Sam captive, having his way with him and Dean was fighting to rescue Sam - I think it ended up that Dean brought the police with him or something when he finally managed to save Sam - or some other hunters I can't remember exactly. (sorry)
And I think that at the start of it there was a time when John allowed other hunters to have their way with Sam too, before he took him for himself. I remember Dean was beside himself about it all and when he finally rescued Sam they like made out on the front step or he held Sam on the front step or something - some show of affection right there on the front step, I remember that because it was the one relief and good moment in so much angst and tragedy.