1877, Charles Loftus, My Life, Volume I., pages 217–218:
However, I could not but turn over in my mind this sudden and unexpected affaire de cœur, which had in so short a time come to a crisis, and which would be likely to create embarrassment, for I was well aware of my dear father's objection to the early marriages of young men without good prospects, and here were few on either side.
1890, William Kingsford, The History of Canada, Chapter VII., page #113:
At this date occurred his affaire de cœur with Elizabeth, eldest daughter of sir Wilfrid Lawson, maid of honour to the princess of Wales.
1900, unknown, The Saturday Review of politics, Literature, Science and Art, Volume LXXXIX., page #814:
It seems strange that to write such lines as those quoted above should have helped Bryon to forget an unlucky affaire de cœur, but such it seems was the case.
1906, John Price Millington, John Dalton, Chapter V., page #91:
He himself confesses to an affaire de cœur which seems to have been something quite out of the common course of his life.