Demi Lovato is to play Naya Rivera's on-screen love interest in 'Glee'.

The 21-year-old singer-and-actress is to star in one of the first two Beatles-themed episodes of the forthcoming fifth season, and Naya - who plays Santana Lopez - can't wait to bring the 'Heart Attack' hitmaker to ''the dark side'' by getting close to her on the musical comedy-drama series.

She told MTV News: ''She's playing my love interest, so I'm very, very excited about that.

''We get to sing a song together. It's gonna be good. I'm excited to work with her. We're bringing her to the dark side. Well, she comes in in a Beatles episode, so [we're singing] a Beatles song. I'm excited.''

Naya and her fellow cast members are currently filming the first three episodes of the upcoming new series, in which they perform songs by The Beatles, and the 26-year-old star has enjoyed singing the legendary British band's hits.

She added: ''We're still shooting them. We're shooting three episodes at one time right now, and it's awesome.

''We get to sing all of the best Beatles songs.''

The 'Glee' cast have also been filming a tribute episode to their late co-star Cory Monteith - who played Finn Hudson in the show - after he was found dead in his hotel room in Vancouver, Canada, in July following a heroin and alcohol overdose. The episode is due to air on October 10.