Okay so, ngl I was kinda thinking about Melli omo even before it was requested so uh. Here, have Some Thoughts (tm).
So Melli is really arrogant and overly confident, right? He's obnoxious and has a huge ego. But he also canonically used to be a REALLY shy and anxious crybaby, if I understand what Mai said correctly.
He just at some point made the conscious decision to act more confident and be bolder about everything. (mainly because he really wanted to impress or be useful to Adaman, it sounds like)
And. I kind of love the idea of the shy/crybaby side of him coming through a little and mixing with his arrogance and desire to appear cool/important in really inconvenient ways.
I can really imagine him bugging Adaman insistently, and Adaman thinks he's just doing, you know. The typical Melli thing, and is starting to get pretty short with him.
But actually, Melli is bugging him because he really needs to pee and either it's a situation where it's unsafe to go alone, or they're really busy and he's supposed to be doing something, so he needs Adaman to cover it for a few minutes (but doesn't want to admit he can't wait).
But like. Annoying Adaman purely for the attention, or trying to make random excuses to get out of things he doesn't like is completely typical Melli behavior? So Adaman has no idea that there IS a reason this time, especially if Melli won't come out and admit that he badly needs to make a pit stop, and no he cannot wait until they're done with the thing/it's convenient.
And like. Melli finally getting upset and telling Adaman what he wants (probably in a whiny or over dramatic way), and Adaman is just like "Fine, Melli, quit wasting time and just go then! Did that really call for such a production?" and covers for Melli. Because like, he never would have even had a problem if Melli just made it clear that he actually had an urgent need, instead of just irritating people.
Except like. At that point it's pretty much too late? Either he was already leaking or on the brink of disaster when he told Adaman, or he was close but okay... Then one tiny thing got in his way and it was just OVER.
So I'm imagining him just whiny crying to Adaman and Adaman coming over like "WHAT N- oh. Seriously, Melli??"
Cue scene following the pic I drew in which Melli is just melting down, and Adaman is torn between being irritated by the sheer theatrics and avoidable nature of the situation (and maybe a little with himself for misunderstanding)... And just feeling bad for Melli and wanting to ease the humiliation/offer some comfort. Melli may be obnoxious, but he's still someone Adaman is close to.
(bonus points if this is in front of people from either pearl clan or galaxy team, because Melli would be much more upset, and Adaman more embarrassed by his overall behavior. I get the impression that Melli is always annoying, but it's dealing with people outside his clan that he really dials it up from "irritating" to "totally unbearable", just because he feels like he has something to prove, and they don't just ignore the theatrics the way his clan mates do.
This is probably a source of great frustration to Adaman, because it means that Melli is most likely to be embarrassing or make him look bad at the exact moments that Adaman would really prefer he was on his best behavior.)