Here’s a brief blurb from the October 25 1938 edition of the Toronto Daily Star about what could be called a May-December romance:
Hewlett Johnson (1874-1966) was a zealous supporter of the Soviet Union. He published a collection of pro-Soviet articles, The Socialist Sixth of the World, in 1939; it was later discovered that much of this book was copied word for word from various Soviet propaganda sources.
His marriage to the former Nowell Edwards (who was his second cousin) produced two daughters. As far as I know, the couple stayed together until his death. She passed away in 1983.