Sometimes, Green really hates Red. He hates that Red has absolutely no sense of self-preservation and would probably die from something stupid like starvation if Green didn't bring him food. Or from hypothermia because it wouldn’t occur to him to wear more than a t-shirt in sub-zero temperatures.
Of course, none of this would've been a problem in the first place if Red weren't so adamant about confining himself to a dark corner in Mt. Silver - which never really made sense to Green anyway since it's not like many trainers find their way there. Not that Green really cares where Red decides to seclude himself except for the fact that it's him who has to make the tedious hike up the mountain every time to make sure Red is still alive.
Logically, Green knows that he doesn't have to do this since the few times he's missed a trip, Red had gone down to pick up supplies on his own and left Green a memento to let him know he'd been there. But not actually bother to go see Green or anything, because Red is just insufferable like that. Green hasn't missed many trips though, and knowing Red, Green tries to justify to himself, he'd probably forget one of these days and would be stupid enough to just go and die. Then Pikachu would be sad, which would make Eevee sad. And Green would never, ever want Eevee to be sad, which is why he still does this.
On his shoulder, Eevee mewls quietly and shivers, curling its tail around Green's neck a little more tightly and draping across his shoulders like an overly fluffy scarf. Green brushes off the snow that has accumulated on the end of Eevee's tail with his free hand, and whispers, "It's okay, we're almost there." He's beginning to find it frightening that he knows the route to Mt. Silver almost as well as the back of his hand, which is a terribly useless skill that - really - no one should have.
Spotting the entrance to the cave, he quickens his pace a little so they can finally get out of the never-ending snow storm that was always brewing outside. As soon as they're inside, Green sets Eevee down on the floor, who proceeds to shake the off the rest of the snow on its coat before hurrying off in whatever direction Pikachu (and inevitably Red) is in. Eevee is much faster at finding the two of them than Green is, and so much better at not walking face-first into walls like Green tends to do when he's left on his own.
"Vui~" Eevee coos happily, and runs up to Pikachu, who's sitting by Red against the wall.
"Pipi," Pikachu chirps and snuggles Eevee's warm tuft of fur before the two run off into the darkness.
Green walks up slowly to Red, who's still sitting, and drags the large package he's carrying behind him. "Geez, it's cold in here," he complains, as if he hasn't complained about the same thing every single time. Red's eyes are fixed on him with his usual deadpan expression, but Green decides that it's better than being completely ignored like Red does sometimes does to him.
He sets the package down next to Red and pulls out the newest scarf he's brought - Red has a tendency to "lose" them every time he leaves - and wraps it tightly around Red's neck. "How do you not freeze to death in here?" he asks for the hundredth time, neither expecting nor receiving an answer, and drapes a blanket over Red whose intense gaze is still following him.
Green resists the urge to roll his eyes and takes out a packet of sandwiches. "Kotone made them for you," he explains, handing one to Red before snagging one for himself - if Red's gonna make him go through the trouble of being his personal delivery boy then he can damn well share - and crawls under the blanket next to Red.
He chatters about trivial and unimportant things as the two of them eat the sandwiches, never pausing long enough for Red to respond (since Red had lost whatever conversational or personal skills he ever had in the last few years anyway). He doesn't really care if Red is listening or not, but it's better than having to deal with the awkward silence that always sits between them when he's not talking.
Finally, he runs out of things to talk about, and Red stares at him at him with this blank yet strangely and irritatingly smug look that Green hates, and just lets the loud emptiness of the cave hang in the air around them, so much that, eventually, Green can't take it anymore. All he wants to do is find Eevee and leave because Green likes being away from his gym about as much as Red likes being away from the cave, and he can safely say that this trip has really taken too long.
He jumps up and announces "I'm leaving!" a bit too loudly and it echoes throughout the cave, but then Red grabs at the edge of his coat and doesn't let go, and says "stay" so quietly that it almost gets lost in the darkness. And when Red pulls him down for a kiss, Green knows that he's not going anywhere any time soon but he thinks - just maybe - he'll be okay with that.
(More than anything, Green hates that he is completely, undeniably, and hopelessly in love with Red.)