Cliquey

[Gregory]

(of a group or place) tending to form or hold exclusive groups and so not welcoming to outsiders.

[PussyCat]

1. [Tending] to form into many exclusive groups of friends which rarely, if ever, mix with each other.
2. Describing someone who organizes his/her [social life] such that all of his/her friends all fit into one or a few exclusive groups ([cliques]).

[Marquetta]

A group of friends metaphorically [giving] [each other] [oral sex].

[Monty]

behaving like a clique, not making other people feel welcome: