Well, in such a fanfiction, perhaps Felicity is kidnapped by an unknown antagonist. The ponytail pull could be a sign of aggression or a way to control her. Maybe she is being held for ransom, or there's some deeper plot like the kidnapper is trying to get information from her. It could also be that a hero will come to her rescue and the ponytail pull becomes a key detail in identifying the kidnapper later.
The kidnapper might be a mysterious figure who has been stalking Felicity for a while. The ponytail pull could be part of their signature way of handling their victims. It could also be someone who is after a valuable item that Felicity has in her possession.
Well, she could be held in a secret location. Maybe Lopez has some ulterior motives, like getting information from Felicity. He might try to use her skills for his own gain.
Well, it could be that the glasses hold some sort of magical power. Maybe a villain kidnaps them to use that power for evil deeds. For example, the glasses might be able to see into other dimensions, and the kidnapper wants to rule those dimensions.
Perhaps Felicity has a hidden power that is only activated when she has her glasses. Without them, she has to find an alternative way to fight back against her kidnappers. This could lead to her developing new skills or alliances within the story.
One possibility is that Felicity kidnapped Lwithout Glasses because she's in love with him and doesn't know how else to get his attention. In the fanfiction, this could turn into a rather strange and intense love story. Lwithout Glasses might initially be angry and scared, but as time passes, he could start to understand Felicity's motives and they might develop a relationship. However, there could also be external factors that try to keep them apart, like Felicity's family or Lwithout Glasses' own responsibilities.
In this fanfiction, Felicity might be an artist who is kidnapped because her squinting and the way she sees the world through her glasses gives her a unique artistic perspective that someone wants to steal. She tries to resist the kidnappers' attempts to make her create art for them, all while hoping for rescue and trying to find a way to escape on her own.
Maybe Felicity has to go on an adventure to find her glasses. She could meet some interesting characters along the way who help or hinder her search.
One possible plot could be that Felicity has some sort of vendetta against the person with glasses. Maybe she kidnaps them to get information. For example, if in the fanfiction's universe the person with glasses has access to some secret technology or knowledge that Felicity desperately needs for her own purposes, like to save a loved one or stop a greater evil. So she resorts to this extreme measure of kidnapping.
Well, it could be a symbol of a past encounter. Maybe the person who was kidnapped was wearing the ponytail and the kidnapper took the hair tie as a sort of trophy or reminder. It might also be used by the protagonist later on to identify the kidnapper, like if they notice the hair tie on the kidnapper's wrist during a chase or confrontation.
The character Felicity could be a complex anti - hero type. She might be someone who has been pushed to the edge by circumstances in the fanfiction world. The person with glasses could be a nerdy scientist type. They could be working on a project that Felicity believes is dangerous if it falls into the wrong hands, so she kidnaps them to either stop the project or control it herself.