fairy tale
1. noun A lie or fabricated account of something (likened to a clearly fictional fantasy story). I know he's telling me fairy tales to avoid admitting his mistakes.
2. adjective Resembling a fantasy story, especially due to being entirely positive or happy or having a happy ending. In this usage, the phrase is usually hyphenated. I really want a fairy-tale wedding, complete with a beautiful gown and a fancy cake. It wasn't some fairy-tale marrage, you know. We had our problems.