Responses
well he did think he was an alpha before so that's most likely where his preferences started
I thought he was just admiring them cuz they look pretty or cool
that could also be it. but remember in the beginning he was trying to marry a pretty and rich omega back when he thought he was an alpha
Hye Sung is the literal gay in this alpha/omega universe (￣∇￣"). Supposedly omega is attracted to alpha and vice versa, but hye sung now attracted to omega same orientation as him... haha.
Which is a clever nod to their original universe If You Hate Me So where hye sung was in denial he's gay (=・ω・=)