If u read the past chapters he's actually the reason why the omega became an omega, the alpha guy presented before him and since they where childhood friends and always together him being in contact with strong alpha pheromones for a long time mad him present as an omega, also the alpha guy scented him without consente which is kinda SA sure he did it to protect him but now the omega can't calm down without him and even pills don't work properly and won't be able to be in a relationship unless it's the alpha who scented him for that long which kinda fucked up. If you look at it that way the omega have every reason to resent him especially since he's in a sport field which make it even difficult but yeah I still think the omega is too mean and could solve the problem in a better way then treating the alpha like a cum slave (￣∇￣")
he's ordering the Alfa around & treating him like trash. if his childhood friend wasn't an Alfa would he be safe?!? it's not like he caused him to turn into an omega, he would still go into heat, get targeted by who knows whom. & then who would save him?!?