
Fraternal twins are not identical. You cannot have identical twins that are male and female. That is impossible. That's fraternal twins.
Identical twins are formed from the same egg and sperm and have identical DNA. Males and females do not have identical DNA.
I can't believe this is something I have to explain. Our education system has failed us.
Gender is a social construct and is fluid but sex is not. Someone who's sex is male will not look like a female without some sort of medical intervention. A wig and a dress does not make a male look like a female. Gender affirming surgery and treatment would not be a thing if this wasn't true.

Right.
The wedding dress was the pinnacle of, "Oh come on!" I'm glad they didn't drag out the "how long can we hide you're male" thing but there wasn't any padding at all to give feminine curves. They already have Oliver in "dude looks like a lady" territory and no one, no one at all second-guessed Kiran in that dress?
Props to the artist for playing it "straight" with the clothing and his body but too many things both visually and in the plot give away the surprise. The only two things in his favor are no one in the new kingdom knows what his sister looks like and that he's young enough that he hadn't broadened out in the shoulders like his brothers yet.
Sticking around for the enemies to lovers dynamic even though the next surprise is as subtle as a brick.
There's been a few of these "let's dress the boy up as a girl and marry them off" manhwa and they never make any sense to me. Obviously everyone is going to know.
Do you know how many years of hormone replacement and surgery it takes for a male to pass as a woman? Throwing on a wig and some makeup just doesn't work long term. You might pass at a glance but it won't last more than a moment.