IDIOMS

skunk at a garden party

(idiomatic) Within a group, someone who is unwelcome and actively avoided.

Example: 1963, A. R. Gurney, The Comeback, ISBN 9780822202295, p. 11 (Google preview):
  "You're making us all feel uncomfortable and uneasy. You're a skunk at a garden party, to put it bluntly."
1996 Aug. 13, Michiko Kakutani, "Books: Confessions of a Big Mouth," New York Times (retrieved 6 Dec 2015):
  Mr. Rollins . . . is probably as well known for his big mouth as he is for his campaign savvy, a quality that has made him a favorite source for reporters and often cast him in the role of "the skunk at a garden party" in political circles.
2009 Feb. 18, Lindsey Hilsum, "Obituary: Alison Des Forges," Guardian (UK) (retrieved 6 Dec 2015):
  "Her work on the abuses being committed by the Rwandan government today made her something of a skunk at a global garden party," said Carroll Bogert, associate director of Human Rights Watch.
2013 July 26, Martin Regg Cohn, "Premiers remain rebels without a common cause," Toronto Star (Canada) (retrieved 6 Dec 2015):
  It’s no fun being the skunk at a garden party. . . . But even after a glass of pan-Canadian beer . . . it must be said: The annual meeting of premiers, now known formally as the Council of the Federation, is a roundtable of rebels without a common cause.