a. sexual relations with them
b. long term relationship/marriage to them
c. reproducing with them

I was at a big family re-union on saturday and I didnt have a clue who half the people were, even though there were somehow related to me. It struck me that you could easily end up accidentally doing a, b or c with an extended member of your family, which scares the hell out of me.

I know legally you're allowed to marry your cousin, but surely no sane person would consider a, b or c with a cousin? would they?

nb. my answers are: a: never. b: never. c: never.