Quoted from Ydoll_Gwyn

My point here was that he doesn't say he's burning the house down!

No, he doesn't.But it's a possibility.

In the usually reliable book A Hard day's Write, Steve Turner says :

John later asked Paul for help with the ending and Paul said he should add some lines about the apartment burning down.Pete Shotten thought this could have referred to John's habit of burning furniture in the fireplace at Gambier Terrace in Liverpool.While he was there, John would sometimes ask guests to sleep in the bath ...

Quoted from Mairi

I've read in several different places that NW was a song John wrote about having an affair... then he changed the ending so Cynthia wouldn't catch on.

(PS, I find it funny how people who smoke pot think EVERY song is about pot )

Yeah, I've read that too. I think it might be true.

You're right about pot Mairi BTW! I also think that every song is about pot!   Just joking.