I don't remember John Wayne having romantic scenes on any of his wagon train movies. Maybe they were there but we didn't notice.
My wife has a wagon train romance in her family history. Her great great grandparents met and fell in love on a wagon train from Saline County Missouri to Austin Texas in 1859.
Louisiana English Pennington was only 17 years old, riding in a wagon with her parents Simeon Dudley Pennington and Mary Jane Lynch Pennington when she met William Smith Telford. He had just finished a tour of duty in the US Army and was riding along with the wagon train on horseback.
He was five years older than Lou and according to a November 23, 1929 newspaper article in the Dallas Morning news he fell in love with her on the trip. They weren't married for another six years because he left to join the 4th (Bates) Regiment Texas Volunteers during the Civil War. After the war he came back to Austin and found Lou had waited for him.
They had twelve children and the second oldest was my wife's great grandmother Kate Augusta Telford Longacare.