I agree with you that the author was going for that feeling, but the point that bothers me is where he references BLEEDING afterwards. I don't care if it's dub-con but dear lord if your partner starts bleeding during sex and you didn't just pop a woman's cherry then you need to fucking stop.
http://www.mangago.zone/read-manga/kajou_mousou_shounen/uu/9cba1c34caea31431330136c134a9c6f_chapter-4/pg-4/
You mention a "woman's cherry", but this was sex between two men, the anus bleeds the 1st time and you will hurt a bit the following morning. You (not you, the general public)can't hate him because the sex lead to "bleeding and soreness" when it is supposed to. Anyone who doesn't know how first time anal works should look it up.
Pfft! There it is! Literally word for word, literally EVERYTHING i said. My condolences to anyone who can't accept the reality of the manga, i'll be fine knowing Oono can! ╮(￣▽￣)╭ I said it all multiple times, but here is where i said it the most recent time: http://www.mangago.zone/home/mangatopic/3079707/
Also: It's not a bad read at all, it was still a very interesting concept with a relatable MC, people just got SO stuck in their opinion that "this is rape" that they weren't open to it when the story made it evident that it actually wasn't. There was dubious consent, it wasn't said aloud, but the sex wasn't with the intention to "rape" Oono. Kureshima was fully aware of Oono's feelings and Oono's denial of them and Oono was aware to a degree of his feelings as well, Oono says he "intended to blame" Kureshima, hence his bad attitude about what happened from the beginning of ch 4 up till the end of ch 4 where he admits he was lying to himself. This isn't an opinion, it's a fact made clear by the end of ch 4 and the entirety of ch 5. If you can't get behind this, too bad, it's the reality. Go read something else because it isn't going to change.