Self Proclaimed Love Interest

A Comedy Trope where one character claims that they are someone else's love interest, even though the two are not actually in love, dating, or (in extreme cases) even anything more than casual acquaintances. This character may exhibit traits of Stalker with a Crush, although they will deny that they are any such thing. They will also become a Green-Eyed Monster if they see their "boyfriend/girlfriend" anywhere near another boy/girl, even though they have no legitimate claim to the person. For maximum comedy, the object of their "love" may find themself dragged out on a date against their will.

Can be Truth in Television. The psychological disorder Erotomania causes an extreme manifestation of this trope wherein the afflicted individual comes to believe that a specific person is in love with him/her and acts based on that belief. The fixation can be triggered by something as innocent as a smile from the person as they pass the afflicted individual on the street.

Compare Clingy Jealous Girl and Stalker with a Crush. Contrast She Is Not My Girlfriend. Also, this kind of behavior is typical of the Yandere.

Examples:

Anime and Manga

• Tokiwa from Ask Dr. Rin! plays this trope for drama while he's posessed. When he isn't, he doesn't fit in here..
• Megumi aka Nodame from Nodame Cantabile, so much. She actually declares herself Chiaki's wife, and some people take her seriously, but they aren't even dating or anything and Chiaki mostly thinks of her as a pest outside of being a genius pianist. She pretty much hangs around him so much that eventually he stops correcting people that she's not his girlfriend, and even starts referring to her as his girlfriend and eventually they get married
• Yu-Gi-Oh!, Rebecca started claiming that Yugi was her "boyfriend" during her second appearance and kept it up through the end of the series. She at least managed to make Yugi blush and Anzu jealous if nothing else.
• Mieru in Yu-Gi-Oh! Arc-V believes Yuya Sakaki is her "Darling". She eventually realizes otherwise when Yuya suffers a major Break The Cutie upon realizing Yuzu's gone missing, and later becomes determined to find her and save her.
• Ranma ½: Tatewaki Kuno, poor deluded fool, is this for any woman he has the slightest interest in. Especially Akane and Female Ranma, who really hate him.
• In Detective Conan, Momiji Ooka firmly believes that Heiji Hattori is her destined love and holds on the Childhood Marriage Promise they made. Heiji doesn't hate her, but he's already in love with Kazuha Toyama. And their promise was not a marriage one.
• The baseball player Takahara becomes this to Koume in Taishou Yakyuu Musume.
• Sweden calls Finland his wife. Finland doesn't approve. It Makes Sense in Context.
• Used somewhat sarcastically by Relena Darlian early in Gundam Wing, when she tells Sally that she's Heero Yuy's classmate and sweetheart. In truth, at this point she's mostly fascinated him for a variety of reasons, her crush on him doesn't develop until sometime later.
  • Even more, at that point Heero was held in a military hospital and Sally was one of the officers watching over him. Relena wanted to check on him and that was the first excuse she probably could come up with.

Comics

• Peanuts: Sally is like this towards Linus. "I am NOT your sweet Babboo!"

Film

• Stuntman Mike from Death Proof seems to have this for his victims, but he's a serial killer, and his feelings weren't Played for Laughs.
• In Singin in The Rain, the in-story main couple are rumored to be together--and Lina goes along with this, because she read it in the tabloids. A few scenes are devoted to Don trying to convince her it isn't true.
• The romantic comedy When in Rome runs on this trope with several suitors enthusiastically chasing the protagonist around.
• The French film À la folie pas du tout (in English, He Loves Me... He Loves Me Not) features Audrey Tautou as an erotomanic who displays this behavior towards a happily married doctor who is barely aware of her existence. She takes his rejection about as well as you might expect.
• Eddie Brock has this opinion of his 'relationship' with Gwen Stacy in Spider Man 3. Gwen comments that all they've done is have coffee together.

Literature

• Deconstructed in Memories of Summer. The title character flirts endlessly with an older man and believes him in love with her, but the man is actually very uncomfortable with her doing this and even begs her father to make her stop.

Live Action TV

• Wizards of Waverly Place had Harper dabble in this trope for a few seasons with Justin before moving on to Zeke. She would routinely talk about her (imagined) relationship with Justin and claim that any other girl Justin dated was only a temporary fascination and that he would eventually find his way back to her.
• C.C. Babcock on The Nanny sees herself as the only woman in Maxwell Sheffield's life, rather than Fran Fine, even though Maxwell sees her as nothing more than his business partner. She eventually gives up when Maxwell marries Fran and the Belligerent Sexual Tension between her and Niles reaches an all-time high.
• Played for Drama on Dexter, when a murder victim's "girlfriend" turns out to be a stalker who killed him in a rage because he didn't return her feelings.

Video Games

• Sonic the Hedgehog: Amy Rose is this to Sonic.
• Sie Kensou from The King of Fighters is this to his best friend and fighting partner, Athena Asamiya.
• Silvia in the Oosawa Mitsuki manga of Fire Emblem: Genealogy of the Holy War refers to herself as Lewyn's wife in one panel. She only does it once, though.
• In Fire Emblem: The Blazing Blade, Serra claims to be Hector's fiancé in her C support with Erk. It's not touched on again after that, aside from Serra claiming all of the men have the hots for her and must envy Erk for getting to be near her.

Visual Novels

• Yoshiyuki Shingu from Shall We Date?: Ninja Shadow is this towards the Player Character, whom he is Childhood Friends with. Depending on which path is chosen, he may or may not be upgraded into her actual boyfriend.

Western Animation

• Panini is this towards the title character on Chowder. The Distant Finale has them eventually married.
• One episode of The Simpsons features a short story set in the 1600s, where Moe declares a widowed Marge his fiancé. She believes it to be more of an "amiable concordance".

Real Life

• Famously, a guy named John Hinckley, Jr. had an erotomanic delusion involving Jodie Foster. It led to him shooting Ronald Reagan to "impress" her.