
Um so I'm still confused then. Why do you think the whale boy wouldn't develop a crush on someone he just realized is the same as him? I mean whale boy's mom did say he had a hard time mingling with humans y'know? And they set them up on a blind date because the teacher told her about the swim class instructor's roommate remember?
All of the above including the latest chapter, btw, demonstrates that blue hair just found out that pink hair is of a similar kind to him so there's no reason to think that blue hair knows exactly who pink hair is.

personally i think whale boy's character is too freaking plastic-- he legit doesn't make sense to me, one time he says he finds him interesting and tries to get a reaction by pissing pink off? and another time he kicks him out of the house?
...and while doing all this he has the same face plastered throughout it all (most of the time), like a cold, genius male lead in every old high school-centred shoujo manga.
i'm finding it very hard to understand what his main motive is-- and whether he's lying or telling the truth. like, he said he regretted what he did almost immediately and tried to contact pink, but couldn't get a hold of him. BUT we were never shown him making ANY efforts to find him after he's gone????? then he says he has a crush on pink with a straight face? no emotion? He said he regretted his actions and and he's playing along with all pink's whims to "make up for it" but he's really just putting up with it for god knows what?
"Why do you think the whale boy wouldn't develop a crush on someone he just realized is the same as him?"
Because... that's just not how it works? Screw development, there wasn't even any build-up to it... and it was just entirely absurd and thrown into our faces out of nowhere?
Like Mark said. It may be curiosity, but it sure as hell ain't a crush.

I was asking the original poster why the sequence of events (since the events themselves are what mainly tells us what's going on not solely the translations) I described in my above post could have made the OP believe that there was no hint when blue hair might have developed a crush on pink hair....?

(Continuing on from my last post, too) If you read the other part of my first post carefully you'll get to the part where I mentioned his mother demonstrating how he had difficulty interacting with humans. We also know that the one time Jiseung demonstrated any emotion was when his dad captured Oh Rino and placed him in the tank. Like I said the reason the the trainer and Jiseung's mom set them up on a blind date together was because Oh Rino was a dolphin who turned into a human, so he was someone Jiseung could relate to. But up until that point blue hair had no idea that pink hair was a dolphin. His surprise when he sees pink hair is evident after all. So it is clear that IS how it works. And that yes there was development..... It's just not certain at this point whether he knows that Oh Rino is the dolphin his dad captured back then.

being pleasantly surprised about knowing someone is like you is not enough to develop a crush. suppose you're working in a foreign land. you feel lonely because you haven't found anyone from your country yet. it's been ages since you've spoken to anyone in your mother tongue. then, a new recruit in your company turns out to be from your country. do you instantly crush on them? or are you just are you pleasantly surprised?
and besides, its blatantly obvious from the recent chap he's just curious about the fact "he was a dolphin all along and he was like me?? since when did he hide it??" which is why he's tolerating pink's tantrums.
alternatively, do you crush on all your friends?
so no, it's *not* like that.
but i'm not denying possibility that whale boy CAN really start liking him later. (which is obvious that he will.)

...You're missing large chunks of the story in your explanation.
1. I didn't have sex with that stranger before I knew they were from my home land nor did I have sex with my friend (even in your examples that is made transparent).
2. Long before they ever had sex, blue hair became interested in pink hair for other reasons (when, before that, he was pretty apathetic towards Rino), which is another crucial point. Because that means even if he lost interest pretty quickly afterwards like it appears he often does, he still became interested in him enough that it lead to them having sex.
3. Combine Jiseung's typically apathetic attitude towards humans with not only the interest he displayed towards Rino after he met the latter for the first time in his human form but also the fact they almost immediately jumped into a sexual relationship afterwards and now the fact that he recognizes Rino is of a similar species to him, you get a pretty reasonable scenario for how someone starts developing a crush on someone else.
4. 'Crush' does not have to be about liking or loving someone.
i kinda got confused with the translation, so can anyone please tell me when did whale boy develop a crush?