So...

I think the ‘hyung’ knew that he is a male lycan but in truth it was the other way around. It might not be his brother that is female but him.
And I think Hwa notices the brother doing something bad like using female pheromones.

I thought in general...if they were born Male and nothing more, they are referred to as males... but if they are born male yet classified as a "lycan" they are internally female therefore are referred to as females. Kinda like an omega. PLEASE correct me if I'm wrong, I'm still trying to figure this out. This story was not really confusing until the kiddos came along...

So Lee Hwa is a male lycan, the Sunbae is a female (he said he marked Hwa aka he knows he’s female). The brother of the Sunbae is probably also a female, but he didn’t exhibit his female pheromones so Hwa thought he was a male lycan. If you remember about Gok (mom), other lycans noticed that he was female because he marked Bin (dad) and didn’t know how to control his pheromones.

Hmm I think no because Ino is a male lycan and that why he tried to mate with Hwa Gok to produce pureblood lycan like Seolhyun. So not every male who is lycan is a female lycan. That's from what I understood from this manhwa and like you, I'm also trying to figure this out too (￣∇￣")

See, I thought lee was deceiving Kim [accidentally] that time because right before they met, , Lee hugged his brother which gave his pheromone onto him [hair cut money] so he kim thought he lee was a female lycan. I dont recall reading male lycan.. now I have to re read....

This is why children should stat out of YAOI!!!! LOL

Not all lycans are female. It's like lycan = wolf. And not lycan = female. If you understand it in the ABO dynamics, female lycans are omegas, they go on heat and can be pregnant while male lycans are Alphas.

It was said in the previous season that Ino is a male lycan (Alpha) while hwa gok is a female lycan (Omega).

Now in this season,

Hwa (son of Hwagok - female lycan and Yebin - Vampire) is a hybrid. Half Lycan/ Half Vampire.
Seo is a female lycan (who was adopted by the elder so he can breed with other pure male lycans)
Younger brother is a male lycan

Although after the accident, Hwa's memories got erased and supposedly Seo's memory as well. But I think since he's marked up Hwa, his memory isn't completely erased. Although he was make believed that he's a male lycan (that's why he thought he's deceiving Hwa) and his brother is a female lycan, when in reality it's the other way around (Seo being female and the brother being male).

Wow, thanks for the clarity... I will have to re read this. It's such a great story.