 When Robert Zemeckis (qv) was trying to sell the idea of this  film, one of the companies he approached was Disney, who turned it  down because they thought that the story of a mother falling in love  with her son (albeit by a twist of time travel) was too risqué for a  film under their banner. In fact, Disney was the only company to  think the first was risqué. All other companies said that the film  was not risqué enough, compared to other teen comedies at the time  (e.g. _Fast Times at Ridgemont High (1982)_ (qv),  _Revenge of the Nerds (1984)_ (qv), etc).