The megastar popped into a children's ward in London before his gig in at Earls Court to chat to some kids who have had some serious diseases.
While he was there he signed a wall, and even though he only stayed for half an hour, the kids were thrilled.
Maria said: "He got all of us a present for Christmas. It was one of the best days of my life."
Phillipa agreed, saying she couldn't concentrate on school when she found out she'd be meeting a celeb.
She wondered if it was Justin, saying: "Oh I'm going to scream if I see him, I didn't know what I was going to do."
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