Bromance is a term referring to an emotionally close but non-sexual relationship between men.
Jared and Jensen's relationship certainly qualifies as a bromance due to their obviously close friendship, which extended to them sharing a house. They have both referred to the closeness of their relationship in interviews, likening it to a fraternal one.
Sam and Dean's relationship also qualifies as a bromance, although the term is not usually used for familial relationships.
- SPN Bromance comm on LJ