I'm looking for a specific fic where Sam notices Dean uses sex when they're teenagers to get what he wanted from Sam, or to punish him when he fought with John etc. Basically Sam notices and gets really depressed and after they separate and come back in the later seasons (AKA Cas time) Sam notices it happening again and runs away because he thinks he's forcing Dean. Cas and Dean have to find him and Dean apologizes. Ring any bells?

Also, any fics where Sam feels unnecessarily guilty and Dean and or Cas has to fix it.