Watch The Bed Sitting Room (1969)

The great nuclear misunderstanding lasted 2 minutes and 28 seconds (including the peace treaty)

The Bed Sitting Room — Comedy, Science Fiction Film (1969)

In the hazy aftermath of World War III, the fallout from a 'nuclear misunderstanding' is producing strange mutations amongst the survivors, and the noble Lord Fortnum finds himself transforming into a bed sitting room.