mickey relation
n.— «Pat and Elaine are what are known in Ireland as mickey-relations. No blood ties, but are vaguely related to someone who is (probably vaguely) married to someone vaguely related to me. You know they way it is. Relations who are your nearest and dearest when they want something.» —“See the tree, how big it’s gone” Primal Sneeze (Ireland) Nov. 8, 2007. (source: Double-Tongued Dictionary)
This is great; it sounds like half the people who claim to be my family! Adding this word to my vocabulary.