Youre literally contradicting yourself sexuality is a spectrum a guy can still be 100 percent hetero and only be into one guy sexual or romantic attraction doesnt automatically force someone to label themselves bisexual its actually pretty common in real life for someone to only like one person of the same sex and still identify as straight stop taking fiction so seriously and acting like every single attraction has to fit neatly into a box
I'll consider you as one of those people who did not encounter this type of heterosexual. I've s friend who's straight as fuck but still fall in love with our other guy friend. I ask him if he's really straight and you know what he said? He said that he tried to see if he's really attracted to men since he caught feelings toward our friend but he said he doesn't feel the same way le what he feels towards our friend. Ay first I tried to suspect him if it's really possible for a straight guy but I guess they really exist.
If you are attracted to the same sex in any way, you are not 100% straight that’s not how it works most people who date the same sex and still say they’re straight most likely have internalized homophobia and in deep denial also yes, it might be fictional, but people can still criticize overused tropes

What do you mean he’s 100% hetero, when he clearly is not. Is bisexuality some sort of incomprehensible construct? The story even hints at Eunsan having interest in men with all the locker room stuff. Do these authors think it makes it super romantic when someone is gay for just one person, or like what is the logic there?