A Nylieg is a couple that comes to your residence (every) weekend and soaks up all extra space. spare bedroom, living rooms and couches. also to be an exact Nylieg this couple must force you to cook the breakfast on Sunday morning, or every morning until they decide to vacate.
Jim: hey Paul you want to hang out this weekend?
Paul: sorry i can't, got a nylieg coming by this weekend?
Jim: how about next weekend?
Paul: sorry they take up all my weekends!
Jim: well that sucks!
Paul: i know, tell me about it!!!
Jim: well call me if they ever leave!