Togepi was a curious Pokémon, and always paid attention the actions and words of others, they interested the young Pokémon. Togepi always noticed how often it was that words and actions tended to express the same thing, because of the times when they did not.
Togepi saw various people who either travelled or spent a lot of time together. They often didn't say it, but Togepi was pretty sure they would have said "I like you" to the other if they had to. After all, they spent a lot of time together, and liked doing so. Togepi was sure those would be their words.
Then there were mean people, who could have said "I don't like you". Like those bad people who kept trying to take big brother. Togepi could have said "I don't like you" to them and meant it. It seemed people tended to say what they meant, normally.
Togepi knew when Mommy said "I love you, Togepi." she meant it. Just like most of the other people who Togepi had seen people say "I love you" to. The actions tended to vary somewhat, but to Togepi love was love, and when people said "I love you" they normally meant it.
There were those who didn't mean it, though. Like when Uncle Brock proclaimed his love to the pink-haired lady at those places big brother would have to go to when he was hurt. Togepi didn't think Uncle Brock meant to lie, or even if he knew he was doing it. So Togepi could ignore his lying.
Yet there were another type of liar Togepi just couldn't ignore. They were different from Uncle Brock; who proclaimed love to every pretty girl (with the exception of Mommy) left right and center. No, these were the people who never said "I love you" even though they would have meant it. Togepi couldn't begin to understand; love made people happy, so why not say it? It was really confusing to the young Pokémon, so Togepi decided to ask about it one night.
Big brother, why don't Mommy and Daddy ever say they love each other?
Pikachu lightly scratched himself as he looked to "Mommy and Daddy", who at this point were on their feet face-to-face, so things were pretty much normal.
"This idiot got us lost again!"
"We're not lost!"
"Well then, genius, where are we?"
"In the forest! Which is in on the way to the next city!"
Both briefly gave up on dialogue, instead just growling at one another, nearly forehead to forehead as lightning flashed between their eyes, their faces locked in that perpetual expression of conflict.
Pikachu sighed, lightly shaking his head.
Daddy's dense and Mommy's stubborn.
Togepi nodded, but didn't really understand. Instead Togepi just continued to watch.
The argument eventually devolved into one of the two things it almost always did ("Oh yeah?" "Yeah!" or "Did not!" "Did to!"), ending with Mommy pulling out her "best friend" and hitting Daddy with it. She walked off in a huff, leaving Daddy groaning as Uncle Brock just shook his head, a smile on his face.
As Togepi watched, Daddy slowly picked himself up, and Mommy eventually returned, the previous tension seeming to just vanish, allowing a revelation to befall the young Pokémon.
There was much Togepi still had to learn.