
So...who's who? If the teacher is the omega, I'm fucking gonna kill myself.

Omegas can be man or woman, but are usually the uke's and the ones giving birth. Though I have encountered a few where they were actually the seme. One was with an Omega x Omega pairing, and another is an Omega who is looking for an Alpha that he can top. That second one is funny as hell, as the Alpha that will end up his partner is the owner of a large company and saved the Omega from a wild animal that the Alpha owned in the first place.

I'm going to throw a celebration if the teacher is the omega.

Boku No High Spec Kareshi-sama is the one with the Omega that is a "Complete Top" looking for a bottom Alpha. It is hilarious!
And Sukijanaitte Hyakkai Tonaeta is the Omega x Omega, though you need to read the whole thing as it happens on and off (they even switch between who is seme and uke) and there is also Alpha x Omega in it. It is a more serious manga, and the omega x omega are more a background coupling.
What...did I just read...????