Strange the stories that get around - I once had a woman tell me that this song was written by a mother about her new-born baby. I'd just sung the song at my gig at a restaurant. "Ewan MacColl never had a baby," said I. But she wasn't convinced. She'd heard the explanation on TV and it was surely true. Recently I heard of it being sung at the funeral of a baby. I've always heard it at as very earthy, and obviously about adult love, but the line, "...ever I lay with you...." is up for re-interpretation I suppose.
Cheers, Joy