A possible plot is that they initially freak out about the body swap. Then, they realize they can use this situation to their advantage. For example, the Wasp in Spider - Man's body could infiltrate some of Spider - Man's old foes' lairs more easily as they might not suspect her. Meanwhile, Spider - Man in the Wasp's body could use her connections in the scientific community to help solve some of the problems he was facing as Spider - Man, like finding a way to reverse the body swap.
Perhaps a plot where the body swap is caused by a villain's new device. They have to work together, even in each other's bodies, to stop the villain from using this device for more malicious purposes. Spider - Man in the Wasp's body has to learn how to communicate with her allies and convince them that he's really on their side, and the Wasp in Spider - Man's body has to deal with the public perception of Spider - Man while trying to track down the villain.
Well, one interesting plot could be that they have to keep their identity swap a secret from their enemies. Spider - Man in the Wasp's body would have to figure out how to use her shrinking and flying abilities to fight crime, while the Wasp in Spider - Man's body would struggle with his web - slinging and enhanced strength but also use her intelligence to come up with new strategies.
One interesting plot idea could be that when they swap bodies, they have to keep it a secret from their enemies. So they have to quickly learn to mimic each other's behavior and powers well enough to not raise suspicion. For example, Ant Man in The Wasp's body has to act all confident and in - control like she usually does during a mission.
Their relationships would change significantly. For instance, their friends might be very confused at first. Spider - Man's friends would see the Wasp acting differently in his body, and vice versa. Their romantic relationships, if any, would also be affected. They would have to explain the situation to their loved ones, and it could lead to some awkward or comical moments.
A great plot could be that a powerful alien artifact has been stolen and Spider Man and Wasp are wrongly accused of the theft. They have to work together to clear their names and also find the real thief. Along the way, they discover a conspiracy that is much bigger than they initially thought and they have to use all their skills and wits to expose it.
One interesting plot twist could be that while in each other's bodies, they have to deal with their respective personal relationships. Mary Jane in Spider - Man's body might struggle to handle his superhero duties and his complex relationships with villains. Meanwhile, Spider - Man in Mary Jane's body has to deal with her acting career and the pressures that come with it. Another plot twist could be that they start to understand each other on a much deeper level. Spider - Man realizes how difficult it is for Mary Jane to be constantly in the public eye and worried about his safety, and Mary Jane gains a newfound respect for the challenges he faces as a superhero.
One interesting plot twist could be that while in Spider - Man's body, Jane discovers a new side of Peter Parker's life. She realizes the daily struggles he has in balancing his superhero duties and personal life. Maybe she accidentally reveals Spider - Man's identity to some of his enemies while trying to handle a situation in a different way than Peter would. This could lead to a whole new set of challenges for both of them as they try to fix the mess and get their bodies back.
I'm sorry I can't directly recommend specific 'Ant Man and The Wasp body swap fanfiction' stories. You can try searching on fanfiction websites like Archive of Our Own. There might be a lot of creative works there with different takes on their body swap scenarios, from humorous to action - packed ones.
A simple plot could be that it's the Wasp's birthday. Spider - Man, knowing her love for unique things, gets her a lemon - infused perfume. They then go on a rooftop adventure to celebrate, looking at the city lights while sharing stories about their first encounters.
One idea could be that Spider Man and Wasp team up to fight a new villain that is causing chaos in the city. Their partnership gradually turns into a romantic relationship as they discover more about each other during their battles. Another plot could involve them getting trapped in an alternate dimension where they have to rely on each other to find a way back home, and during this time, their feelings for one another deepen. A third plot might be that Wasp is in danger and Spider Man has to go to great lengths to save her, which makes her see him in a new light and start a relationship.
Maybe in the fanfic, Spider - Man and Wasp are framed for a crime they didn't commit. They then have to prove their innocence while also dealing with other superheroes who are after them. They would need to combine their skills, with Spider - Man using his strength to fight off attackers and Wasp using her stingers to defend themselves when in close combat.
One possible plot could be that Spider - Man and Wasp team up to fight a villain who has a strange connection to lemons. Maybe the villain is using lemon - based technology to create chaos in the city. Spider - Man's agility and Wasp's ability to shrink and fly would make for an interesting dynamic as they try to figure out how to stop the lemon - themed attacks.