I just found this

It’s honestly a very very tricky and grey situation because albeit the Omega was unable to give proper consent as they were not in the right mindset, similarly to those when intoxicated, he still did initiate everythinf and “pounced” on the alpha. That’s why everyone suggests for those to not have sex while under the influence, because you don’t really know if you wanted it then or not and people always go back on their word and blame it on the other person as rape, even if there is some validity to it. Overall, I don’t think its rape but its not something i’d like to see occur between any couple tbh. Consent is the SEXY.

Omega was in heat --> He wasn't in his right mind

And pheromones in ABO worlds (esp when omegas are in heat) are extremely powerful and it is in an alpha's nature to 'mark' an omega in heat. Resisting such strong natural instincts tend to be hard. Not to mention this is a different world, you can't exactly use the common sense/ thinking of our world for certain issues.

When committing a crime, there's always the intention and the actions carried out. The actions of the omega shows that he raped the alpha. However, his intention matters just as much as the actions. He wasn't in his right state of mind and the nature of his heat is, unfortunately, unavoidable. This leads him to forcefully having sex with the alpha. The intention of the omega in this case would be more important than his actions (it's not for all cases).

So I would say he did not rape the alpha ON PURPOSE, which I highly doubt is a crime in ABO worlds.

Same goes for the Alpha. He's affected by the hormones, natural instincts take over his thinking, he has sex with the omega. Both don't give consent and they are uncapable of giving consent because they are being driven by strong natural instincts. Alpha isn't raping the omega ON PURPOSE.

Now what happens AFTER the sex would be the real crime...

Oh and BEFORE the sex, can't discriminate