okay i read the manga (should have done that beforehand, my bad) and i would have to agree with the doctor. it's not really rape and hence have removed the tag. blackmail's correct
Your judgement goes against site tagging rules:
"Rape [Forced or non-consensual sex.]"
This is clearly non-consensual sex as I outlined above. It should therefore be tagged as rape. If you disagree with the rules then you should discuss it with the moderators and staff who make the tagging rules. Just because people who read hentai don't want to call rape under threat of blackmail rape, or don't want to call rape due to withdrawn consent rape, means nothing. It's still rape. According to the law, and according to this sites rules. Wanting it not tagged is intentional minimization of rape and misrepresentation of consent, and that's pretty gross. Look at the content all you want, no kink shaming here, but talk about it honestly.
Also note, multiple tags can be appropriate for the same event. In this instance it is blackmail leading to rape, so it requires both tags.
Even if there was no blackmail, if consent is revoked and the sex doesn't stop it is rape. The idea that BECAUSE the person is a victim of blackmail then sex where consent is withdrawn isn't rape, but if consent is withdrawn without blackmail it is rape is incredibly flawed thinking.
The rules are clear. Non-con sex is rape. You can't consent when threatened. So it is rape. She also tells the guy to stop and he doesn't. That on it's own is rape. It's a rape double whammy. Rape doesn't have to be violent, pretending it does minimizes rape. I mean read the rule "Forced OR non-consensual". Kinda confirms that it doesn't have to be forced to be tagged as rape on this site.
Back to the multiple tags thing, if it was a violent rape then you could tag it with violence and rape, and so we are clear, even if she then did the hentai thing and went all "my hips are moving on their own" or "uwahh now I'm addicted to your penis" stuff (like she does in this manga), it would still be rape. Because consent wasn't given to begin with.
On a side note, NTR can be consensual, sometimes you just decide you want a new/old, bigger/smaller, dick and/or pussy because the old one isn't doing it for you, I didn't bring NTR up at all. The NTR aspect has nothing to do with this being rape. The rape is what has to with rape. If the girl just saw the ex again and got super turned on and chose to have sex with him again while lying to the bf, that obviously wouldn't be rape.