I think that omega1 is not accepting the alpha because he knows his friend, omega2, is in love with him. That's why he gave him the bottle the alpha had given him. I am sure omega2 even bumped into the alpha at the beggining on purpose.
But after they had sex omega instantly remembered the face of another omega and pushed him away. Also I'm kinda suspicious of having 2 omegas, like I think the one who is supposed to me omega is actually beta and that they changed identities or something bcs if alpha is chief Chie he would know that there is one more omega but it was written on his data that he's beta
I think this is something like a love triangle or something. Main alpha and main omega both like the same person who is also happened to be an a omega.
I think I will like it bcs it's kinda different and it's not a alpha-beta or omega-beta story that are popular now. Whenever I search omegaverse there is more story's like that than alpha-omega ones I readed a lot of then so I kinda got bored or usual beta-alpha thing.