
Consent is crucial in all forms of sexual interaction. If you don't consent to having a sexual encounter it is rape. The human body is weird sometimes you can feel pleasure during the most despicable actions, but it is still rape.
And if you consent and the sex is bad that's on your partner, but that is not rape. Just bad sex. However, if during the sexual act if consent is rescinded then it becomes rape if the encounter continues.

Feeling pleasure from it is a phsysiological/biological response and it is involuntary and cant be controlled, in no way is it consent
I want to add that many victims cope through their SA by trying to convince themselves they enjoyed it or didnt mind it, usually because they feel blame for what happened (grooming, coercion, victim blaming, etc) or to reframe it to reduce psychological distress. Its a trauma response from the brain.
For the second part, consent can be revoked AT ANY POINT, if a person changes their mind or is uncomfortable and they voice it its revoking consent. Sometimes they might feel pressured not to/feel guilty/etc to where the other person should to recognize that and stop but sometimes they dont notice, some reasons for it are normal some reasons bad
Im talking about real cases as well bc its so important to recognize this behavior irl and not being able to see it can be dangerous, remember that the things u see in bl are fetishes/kinks/and problematic depictions of relationships that are not accurate or realistic
Theres no such thing as seperating the fiction and reality if you think the actions in it are justified in a view of actual consent
Is it still grape if for example the uke doesn't consent but likes the sex? Or also the uke consents but doesn't like the sex and he feels uncomfortable and forced? I'm lowkey confused.