Make-up artist Sir John "freaked out" when he realised Beyonce was a new client. Sir met Queen Bey without warning backstage at Tom Ford's first womenswear show in 2010, when he was introduced by his friend and fellow make-up artist Charlotte Tilbury.
Charlotte had another surprise in store, turning to her pal and telling him he'd be taking care of her make-up.
After a mini panic, Sir calmed down as the superstar quickly put him at ease.
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"When I saw her (Beyonce) for the first time, I thought, 'You're a real person! Oh my God, this is crazy!'," he shared during an interview with People magazine, admitting the pair quickly became fast friends.
"We're the same age and I think we hit it off that day," he remembers.
But Sir John won't officially confirm anything about the special new mini-me in his life - the Formation hitmaker's newborn son Sir.
"I think that she (Beyonce) has been a huge blessing in my life," the older Sir notes, adding with a laugh, "And I love her son's name!"
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Though he credits Beyonce with making him more famous in the make-up world, he doesn't think of himself as a household name just yet, but his name started to carry more weight once his most famous client released her first visual album in 2013.
"I still feel like I have such a long way to go," he adds.
For now, he's focusing on all of his celebrity clients, including actress Priyanka Chopra, supermodels Karlie Kloss and Joan Smalls, and tennis great and new mum Serena Williams.
He can also be seen on TV as a mentor on U.S. network Lifetime's beauty competition series American Beauty Star.