The 26-year-old star plays Santana Lopez - who enjoys a same-sex relationship with 21-year-old Demi's character, Dani - and they perfected their raunchy scenes by rehearsing off-set beforehand.
She told Access Hollywood: ''I made out with her in my trailer before we shot the scene. So then I just, like, warmed her up. You know what I'm saying.''
Naya has enjoyed spending time working with the teenage idol, who is guest starring as a struggling artist in New York City who befriends Rachel (Lea Michele) and Santana, and was glad to have had her on the hit musical comedy.
Naya added: ''She's awesome and we're having a blast and we're so happy to have her.''
'Made In the USA' hitmaker Demi is set to make her 'Glee' debut on an episode which airs in the US on October 3 during the second part of the comedy's two-part extravaganza dedicated to The Beatles.