Move Over, Darling (1963)

Five years to the day after his wife Ellen disappeared in the sea after a plane crash, lawyer husband Nicholas has her declared legally dead, remarries and sets off to Monterey with new wife Bianca. The same morning, Ellen arrives home after being rescued by the Navy from a desert island and follows to try and prevent the honeymoon developing further. Nick, still in love with Ellen, is delighted to see her but finds he still can't break the news to Bianca, while Ellen equally hasn't got round to telling the children she is their mother. Could get complicated.