I'm not sure specifically what 'Cap deage' means. It could be a very specific term, a misspelling, or something relatively unknown. It might be a proper name, a local term in a certain area or a very niche concept.
I don't have enough information to say exactly who Cap'n Kathy is. She could be an original character created by the fan fiction writer. Maybe she's a pirate - the 'cap'n' part could suggest that - who has some connection to the wizarding world of Harry Potter.
One great storyline could be Izuku spending his summer training with a new, secret mentor. This mentor could have a unique quirk that helps Izuku develop a new aspect of his power. For example, he might learn to control his One For All in a more precise way, like being able to focus it on just one part of his body for a short time. Another storyline could be Izuku going on a summer adventure with his classmates to a place full of rare quirks. There, they encounter various challenges and Izuku has to use his wits and strength to get them out of trouble. And finally, a story where Izuku discovers a long - lost relative during the summer who has some connection to his quirk and his family's past.
I can't answer the question about "my wife's 18-year-old episode" because this kind of plot is not common and has no practical significance. The plots of online novels were usually fictional and could not be used as a reference for real life. If you have any other questions, I'll try my best to answer them.
The cap man and monkey story is an interesting one. There was this cap man who was traveling around selling his caps. He reached a place near a forest and decided to take a rest under a tree. While he was sleeping, the monkeys in the tree noticed the caps. They climbed down, grabbed the caps, and went back up the tree. When the man woke up, he was confused at first, then saw the monkeys with his caps. He was worried as those caps were his livelihood. But then he remembered that monkeys often mimic human actions. So he took off his own cap and tossed it. The monkeys, being the imitators they are, did the same with the caps they had taken, and the cap man got his caps back.
Spider - Man's light - hearted and quippy personality can provide a contrast to the more serious and stoic members of Team Cap. His sense of humor can lighten the mood during tense situations. For example, in a battle, he might crack a joke to ease the tension among the team members.
No. Spying is generally not ethical. In relationships, trust is fundamental. If you suspect something wrong between your wife and your friend, it's better to communicate openly rather than spying. For example, in most healthy relationships, talking it out clears misunderstandings.