
I think it's true that's it's always a bit tricky in Omegaverse. But the uke made it clear multiple times that he didn't want to sleep with the seme/alpha. I think just because the uke is fine with it now, doesn't mean it wasn't rape. If this wasn't omegaverse you could maybe say that the uke was willing in the end (still wrong though), but since it is, it's pretty obvious that the uke wasn't in his right state of mind and wouldn't have made the same decision if he wasn't in heat.

Also I really don't want to blame the victim, but we can't deny that the uke was at fault too. The seme begged him multiple times to take suppressant, but he stubbornly refused. Despite hating the after effect, he should've do that and the whole rapey thing wouldn't happen. We can't really blame the alpha because we can see that he desperately tried to fight his instinct, but he was trapped at that time that he couldn't escape from it. It's a situation where both are unwilling, I think that's what makes it even more tricky

Honestly It's not about who is at fault, but I'm just saying that the Seme raped the Uke, it is what it is. Rape isn't defined by who is at fault but by having sex with someone against their will. If a woman walks naked into a prison full of men and they assault her, we can all say she had it coming and it could have easily be prevented by not doing that, but it doesn't change the fact that she was still raped.

But those men in prison are normal person who should've been able to control themselves, they could've just close their eyes or face opposite the woman while the seme lives in omegaverse where he is an alpha whose instinct is supposed to be similar to a dog in heat, and he could do nothing to avoid it because it works with scent. Even if he hold his breath it wouldn't work for long except he wants to die. And I doesn't mean to put the blame on one of them, I'm just saying that they're both have part on that accident that makes the rape in this story got more tricky. But in normal world, the wrong would always be the rapist no matter what, nothing could change that.
It's true I was bit disappointed that the Seme lost control in the last chapter and raped the uke. But It's really nice to see the Seme not only admit his mistake, but also talks about protecting and pregnancy test.