The couple were dinning at Giorgio Baldi Italian restaurant in Santa Monica, California when a fan joined them suddenly on their table, reported People magazine.
The boy posted a picture of him going through the menu sitting with the couple smiling.
"Awesome dinner with mom and dad," the fan captioned the photo.
According to the fan, the pair did not seem to mind the extra company on their date. "(Taylor) is sooo nice," he later commented on his photo.
Swift, 26 and Harris, 31 made their relationship public early last year.
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