He isn't an omega tho... ;)
Wait spoil me please what is he??
He's a beta (=・ω・=) but well not quite
Spoiler below
He's a special kind of beta known as a diamond dust which essentially means he has pheromones and can sense pheromones but it only works with ghost alphas which is what the seme is. A ghost alpha is basically someone who can turn a beta into an omega through sexual intercourse and knotting. There's basically no info on diamond dusts except for a really old diary that was written by a ghost alpha long, long ago and at the time, that ghost alpha called his beta his diamond dust which is why the name stuck. Other than that, nobody even knows that diamond dust betas exist. Ghost alphas are more well known than diamond dusts but they still have very little info on them. People think they are a myth or a legend that doesn't really exist.
Mc always does those wonyoung wink poses.. cant be mad tho he looks so edible!! Also poor boy he doesn't know he's an omega! He really does not know any better stop teasing him!!!