She Is Not My Girlfriend / Live-Action Films

• That Thing You Do!: A variation. James Mattingly goes nonlinear when he sees the "Careful girls! He's engaged!" during their big TV debut. (It was a reference to the "Sorry girls! He's married!" caption during The Ed Sullivan Show performance by The Beatles.)
• In The Big Lebowski, The Dude is quite insistent that Maude Lebowski is not his "special lady," but his "fuckin' lady friend, man!". Probably an example of Insistent Terminology too.
  I'm just helping her conceive, man!
• In Entrapment, Sean Connery's character said this word for word unto Ving Rhames' character when his relationship with Catherine Zeta Jones' character was questioned.
• Friends with Benefits: Dylan and Jamie both say this for each other, but Dylan more strongly and harshly when pressed by his sister. Jamie, of course, overhears.
• Ghostbusters (1984). Peter Venkman denies that a ghost-possessed Dana is his girlfriend. He claims to only find her interesting because she is a client and she sleeps above her covers.
  "Four feet above her covers."
• In How the Grinch Stole Christmas!, when Cindy Lou is interviewing adults about the Grinch:
  Martha May: Did I have a crush on the Grinch? Well, of course not!
  Cindy Lou: I didn't ask you that.
  Martha May: Oh. Right.
• In MirrorMask, Helena insists to her mother that Valentine is not her boyfriend.
• In Mortal Engines, Tom is assumed to be Hester's boyfriend by the crew of Scuttlebug, which he naturally denies given the two's less-than-rosy relationship at that point.

• The musical Oklahoma! has a song called "People Will Say We're In Love", where the two main characters (who get married in the end) tell each other how to behave so people won't assume they're sweethearts (doing each thing they describe themselves not doing, naturally).
• Pee-wee's Big Adventure: Pee-Wee is constantly having to reiterate that Dottie is not his girlfriend. It's a variation on the trope, however, because the only person who seems to think that she's his girlfriend is Dottie herself.
  "...look, Dottie. I like you. Like. I—like you!"
• In Piranha 3D, Jake constantly denies that Kelly is his girlfriend, and the awkwardness is ramped up because he's on a yacht surrounded by beautiful porn stars. Kelly agrees to do a bodyshot off one of these porn stars just to rile Jake up a little.
• Remote (1993): Randy Mason tries to invoke Just Friends about him and Judy Riley when Jamaal suggests that the two are in love with each other. In actuality, it's this crossed with Everyone Can See It.
• Sharkenstein: After Duke saves Coop and Madge from Sharkenstein, while conversing with them, he assumes that they're a couple, which they both deny.
• Joked about in The Silence of the Lambs. "People will say we're in love."
• This is Spın̈al Tap. In David's case, he insists that Jeanine is not his wife. (Not at the time of the film, anyway.)
• In The Little Rascals film, "Hi-Neighbor", this is Wally's response when Jane appears and Stymie says "Wally, here comes your girl." Stymie is not impressed with Wally's denial.
• In The Dark Knight Rises, after Selina beats up a bunch of mooks to help Bruce and Lucius escape:
  Lucius: I like your girlfriend, Mr. Wayne.
  Selina: He should be so lucky.
• Averted in Jurassic World. Seeing Owen Grady motorbike-riding though the jungle with a pack of Velociraptors, the kids congratulate Claire Dearing on having such a badass boyfriend. Even though Owen is not her boyfriend (their first date was a disaster, so they split up before the movie) Claire just smiles at the thought instead of making a vehement denial. They've already shared The Big Damn Kiss after all, when Claire saved Owen from an attacking Dimorphodon.
• In Puppy Swap: Love Unleashed, Sally Ann is clearly attracted to Mel but Mel only sees her as a friend, clarifying it to Jessica when she sees her and thinks they're together.