Road, You Gotta Take Me Home

Summary: After his ex-girlfriend is killed in a car accident, Dean gains custody of her fourteen year old son. They know it’s going to be difficult, with the stress of grief and unfamiliar living conditions weighing on them, but neither of them is ready for just how difficult it really is, trying to feel out where they belong in the confusion and aftermath of such a great loss. They deal with it though. They’re family. What other choice do they have?
A family drama, featuring Dean as a new single father, Ben as a ninth grader with trouble coping, Sam as the voice of reason and the rock that holds Dean up and Cas as the sympathetic police officer who repeatedly busts Ben for petty crimes.

It does have some Dean/Cas in it, but it's mostly about Dean and Ben.