lonely for something to touch
They're dangerous, the Winchesters, both on the edge. Gordon tells them he has the hunt taken care of, knowing they'll show up anyway because Dean is looking for something to kill and he hasn't yet slipped over into killing people.
Gordon's glad for that when they save his life, and he invites them out for a drink.
Dean's dangerous, a hunter like Gordon, but Sam is squeamish, constantly pulling in Dean's instincts, chaining him. Dean loves the kid, though, so he can't see it.
Gordon needs to convince Dean to ditch his little brother, come with him. He can hone what John Winchester(scary bastard) started. Dean could become the greatest hunter in America, if he got rid of Sam's stifling presence.
It'll be hard, but Gordon's never shied away from a challenge.