The Twilight star admitted that she was too shy to get the VIP treatment when she was with the singer at the recent Coachella music festival in California.
Stewart told Jimmy Kimmel on Monday's (May 7) episode of Jimmy Kimmel Live!: "I have a buddy who has absolutely no qualms being in front of millions of people. I'm not dropping - I feel like a weirdo right now - I was with Katy Perry.
"I walked behind her through the entire [crowd]... she wanted to sit up front. She's like, 'Hey, you want to go watch the Tupac stuff? It will be awesome.' I was like, 'Yeah!' "
Stewart - who is promoting her new movie Snow White and the Huntsman - admitted that she suddenly got shy as the 27-year-old 'Last Friday Night' singer drew attention to them in the crowd of music fans.
She continued: "And then suddenly I was like, 'What are you doing to me? Ah!' And I suddenly had to put my hat down, because we were literally like Moses parting the waves of Coachella getting to the front. I was like, 'Where am I right now?'"
When Kimmel asked: "You were in Katy Perry's wake?", the actress replied: "I was like, her entourage. I was leading her entourage."
Kimmel then quipped that Stewart could use Perry to go "incognito" in public.
"Exactly. No-one looks at you, it's perfect!" Stewart added.
Watch a clip of Kristen Stewart on Jimmy Kimmel Live! below: