The singers hung out together at the BRIT School in south-east England, and Jessie said that when they meet up, all their success goes out of the window and they get back to their roots.
She told Contact Music: 'Adele and I used to hang out together at the BRIT School and sing together. I bumped into her recently and she was like, 'Baaaabe!' We're so common when we're together, it's hilarious.'
And when she is not socialising with other chart stars, she said she likes to spend time with her family – in her pyjamas.
She added: 'I'm able to be in my pyjamas and have no make-up on in front of my family - there aren't many people I can do that with any more. My sisters are like best mates and I can phone them and cry and say I've had a bad day and they don't judge me.'