I agree. Kurose sort of an ass in general, so a pissed Kurose is even worse, lol.
I agree with the poster who said it's just bad writing because Kurose doesn't know what we know about the girl. He's not that crude and twisted that he'd have such an over-the-top reaction to a girl coming on to him. If Kurose knew who she was and what she'd done, then it would have been perfectly understandable. As is, bad guy or not, it doesn't work--at least not for every reader, hence the polarized reactions here.
I don't think it's just because she came on to him. I think it's because she was being so horrible to Shirotani, and then she hit on Kurose after she obviously upset Shirotani. That's why many reader's think his payback makes sense.
It works for me. *shrugs*
You know, someone recently made a very good point that made me look at the situation in a new light, and it's that she basically slut shamed Shirotani, more or less. It doesn't make the action any better, but it definitely gives it a whole new perspective.
That's an interesting way of looking at it. She was at the very least insulting him in front of Kurose, which is never cool.
Kurose-kun's slut-shaming and use of the word "bitch" aren't okay, BUT it works in this context because he holds no illusions that he's a good guy, and he embraces the side of him that is sort of crude and twisted. Add to that the fact that he's pissed as hell? Basically, I don't think the mangaka is excusing the behavior, it's just indicative of Kurose's character. And man, that was SAVAGE lol.