Walk the Line
Johnny Cash actually gave June Carter a spontaneous, on-stage proposal
This movie does have its share of inaccuracies and embellishments, but this scene isn’t one of them. While singing a duet, Johnny stops and asks her to marry him, also pouring his heart out to her. She obviously says yes.
This happened on Feb 22, 1968, in London, ON, Canada, and they were married a week later in Kentucky.