The song is McCartney's go-to when it comes to last-minute collaboration, and he again broke out the tune at his nephew's wedding over the weekend.
TMZ reports that the nephew is from McCartney's wife Nancy Shevell's side of the family.
You can watch a clip of the performance in the video above. Needless to say, everyone looks like they're having a great time.
McCartney famously performed "I Saw Her Standing There" with Billy Joel, when he made a surprise appearance at Joel's 2010 Last Play at Shea Stadium concert.
Meanwhile, McCartney is getting ready to release his first new album in five years. Little is known about the new album, except that it contains the song "Come Home to You," which the former Beatle recently debuted at a secret concert in Liverpool.
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