superficial or not?

Jay Gatsby and Nick Carraway have a very interesting relationship up until now in the book. Nick is a more quiet person, keeping to himself. Jay Gatsby seems to be the same way, however, he is always having parties and big events. The strange thing about Gatsby is that he never interacts with his guests. What is his reason to keep away? 
Nick Carraway did not even know Jay Gatsby personally before they became "the best of friends". Nick himself doesn't even know how everything fell into place. Out of nowhere, Gatsby decided to befriend Carraway and spill his personal life to him. Before long, Jay would invite Gatsby to dinner, out places, and for every occasion. Since Nick is more of a follower, he said yes to Jay whenever he asked to hang out and they spent their time together often. 
Is Jay Gatsby's and Nick Carraway's friendship real? At this point, nobody can really tell for sure. They seem to get along just fine. On the other hand, the whole Daisy situation shifted my view upon their relationship. As soon as Jay finally got to meet with his old lover, Daisy, he didn't act the same towards Nick. Fitzgerald includes the line "They had forgotten me, but Daisy glanced up and held out her hand; Gatsby didn't know me now at all.", showing just how clear Jay made it that his friendship is superficial. Even though it seems as if Gatsby is being a total fake, nobody can tell whether or not he's going to stay that way until the end.