Rihanna and Sir Paul McCartney haven't worked together since they released music in 2015 but that didn't stop the two musicians from joking around on a flight from New York City to London.

The 31-year-old fashion designer and the 77-year-old Beatles member bumped into each other Friday in the first-class section of their international flight.

RIHANNA FLAUNTS HER FIGURE TO ADVERTISE NEW LINGERIE LINE

RiRi documented them joking around on Instagram Stories, calling the occasion a "RihUnion."

"I'm about to put you on blast, Mr. McCartney," she laughed. "How are you on my flight?! Who is this peasant filming this legend?!"

"Who is this filming me?" joked McCartney. "Yeah, that's what I mean."

PAUL MCCARTNEY CLAIMS JOHN LENNON LIKED ONLY 1 OF HIS BEATLES SONGS

The unexpected duo last teamed up in 2015 on their single "FourFive Seconds" with Kanye West, which they performed at the 57th annual Grammy Awards and at the Desert Trip Weekend in 2016.

Paul McCartney (L) and Rihanna perform on Day 3 of Desert Trip Weekend 2 at the Empire Polo Field on October 15, 2016 in Indio, California. 

Paul McCartney (L) and Rihanna perform on Day 3 of Desert Trip Weekend 2 at the Empire Polo Field on October 15, 2016 in Indio, California.  (MJKIM/MPL Communications via Getty Images))

McCartney told DIY how "FourFiveSeconds" originated. “We ended up just talking a lot," he explained. “I played a few little things and one of them ended up as ‘FourFiveSeconds’ with Rihanna."

PAUL MCCARTNEY'S FIRST MEETING WITH JOHN LENNON BEFORE THE BEATLES WAS 'UNREMARKABLE,' PALS CLAIM

"It’s more a question of me feeling lucky that these people are interested [in working with me] and think that I can bring something to it. For me, I feel great. I like diversity," he added.