3 specific fics
#1,#2 and #3 found in comments ! You guys are on point !
1. Dean and Sam are in high school and John is off hunting. Dean is sleeping with his female teacher in exchange for money and food. He hates it and gets sick when he gets home. I believe there are sequels where Sam and or John figure(s) it out.
2. Dean is targeted by a vampire who entrances him and has sex with him while he's in a dreamlike state. He winds up being taken by the vampire. Sam and John go to rescue him but actually rape him in a crowded basement instead. I remember there being the concept of elder vampires.
3. The 3rd I believe by the same author as # 2 . It's John/Dean but Dean is mentally browbeat into giving into his father's advances. At one point John is possessed by YED and is even more of a depraved partner than usual coercing Dean into giving in having src in front bathroom mirror and rimming him on the kitchen table. Sam walks in at one point
If anyone knows about these it'd be great.