A possible scenario is that Ginny is chosen to represent Hogwarts in an important inter - school event. She then has to practice with students from other schools, and one of them seems to be getting a bit too close to her for Harry's liking. Harry starts to feel jealous as he sees Ginny having a great time with this new acquaintance and wonders if she might like this person more than him.
In some fanfictions, Ginny might start spending a lot of time with a group of friends that Harry doesn't really like. She seems to have more fun with them, laughing and joking around, and Harry feels jealous because he wants to be the one she has the most fun with. Also, Ginny could receive a lot of fan mail from admirers after she does something heroic on the Quidditch pitch, and Harry can't help but feel a bit jealous seeing all the attention she's getting.
One common scenario could be Ginny flirting with another boy in front of Harry. For example, she might dance with a popular Quidditch player at a Hogwarts party while Harry watches. Another could be Ginny getting a lot of attention from an older student for her academic achievements, and Harry starts to feel left out and jealous. Maybe Ginny is also asked to be a partner for a special project by someone other than Harry, and she seems really excited about it, which makes Harry green with envy.
One plot could be that Harry is partnered with a new female student in a project at Hogwarts. He spends a lot of time with her, studying in the library and discussing magical theories. Ginny sees them together often and starts to feel jealous. Harry might not even realize at first how his actions are affecting Ginny.
One possible scenario is that Harry masters a new and powerful form of magic that Voldemort has been unable to attain. For instance, if Harry discovers a way to combine different branches of magic in a unique way that gives him an edge in battles. Voldemort, who has always been obsessed with power and being the most powerful wizard, would surely be jealous of Harry's newfound abilities.
One possible scenario could be that they are in the Gryffindor common room. The fire is crackling, and everyone else has gone to bed. Harry and Ginny sit on the couch, and slowly start to get closer. Their eyes meet, and then they share a gentle kiss that gradually becomes more passionate as they let their feelings for each other take over.
One common theme is unrequited love. Harry might be in love with Ginny but unable to admit it, so he feels jealous when she's with Dean. Another theme could be self - discovery. Through his jealousy, Harry realizes his true feelings for Ginny.
The theme of envy is also very prominent. Dudley envies Harry's connection with Ginny, which is often portrayed as deep and loving. He may also envy the magical world that Harry and Ginny are part of, which adds another layer to his jealousy. Another common aspect is Dudley's struggle to come to terms with his own feelings, as he's not used to feeling so envious.
One scenario could be that Ginny has prepared a special surprise for Harry in the common room. She has decorated it with floating candles and their favorite flowers. When Harry enters, she plays a soft, romantic song on her wand - charmed radio. They then slow - dance under the candlelight, lost in their own world.
Another situation could be when a new male character enters the story. Let's say a powerful and handsome demon arrives. If Kagome shows any interest in this new character, like asking about his powers or his world, Inuyasha would feel jealous. He would puff out his chest and try to show that he is more powerful and a better choice for Kagome. He might even start a fight with the new character just to prove his point.
A typical situation is when Bulma has to attend a social event with an old friend who is a wealthy and charming man. Vegeta, who is not used to such social settings and is insecure in his own way, would see this man as a threat. He would watch them closely at the event, fuming silently and getting jealous because he thinks Bulma might be attracted to this more 'civilized' man.
A third scenario could be jealousy. If other witches start showing interest in Harry and he doesn't immediately and firmly shut it down, Ginny might get mad. She is a proud witch and doesn't want to share Harry's affections, and his seeming indecisiveness in such situations could lead to her anger in fanfiction.
Well, a major theme is the struggle with emotions. Harry is used to being in control, but when it comes to his jealousy towards Ginny, he's all over the place. Also, the theme of growth is there. Through dealing with his jealousy, Harry grows as a person and becomes more understanding in his relationship. Plus, there's often the theme of the power of love, where in the end, love overcomes his jealousy.