ONCE UPON A TIME. (also known as, VAGUE DESCRIPTION)

I read a fic where Sam had been mentally damaged somehow... I think demon blood or maybe Lucifer leaving him after using him as a vessel? Dunno.

It was Sam/Dean/Castiel/Gabriel, where the other three basically look after him, and his out of control abilities.

The only scene I remember is one where Sam is resting against Gabriel on a couch, and Gabriel tickles(?) him, making Sam laugh and lose control, and a lamp explodes. Gabriel fixes it with a snap, and there is a comment on him being good at this because of how good he was with the fledglings.

Hopefully one of you lovely people know the fic Im talking about! Thankies in advance. :)