that Shirley MacLaine movie

Just catching this on TBS for the first time; turned it on 20 mins before it ends. In the scene where Shirley MacLaine is looking for her husband (Hector Elizondo) at the outdoor movie theater, a movie starring a younger Shirley MacLaine is what's playing on the screen. Anyone know what movie it was? I wondered if she was repeating the line in the movie as she talked to her husband; it kinda looked like it.