Mountain Trippin' by hellhoundsprey

Mountain Trippin' - hellhoundsprey
3.5 stars. Fifteen year old Sam is trying to pull away from Dean to lead a life of his own. It all comes to a head in a cabin with Dean and look-alike Thomas under the influence of alcohol and marijuana. Jumps rapidly from one pov to another. Consent issues.
Source: http://archiveofourown.org/works/2795333?view_full_work=true