“Sexual assault” has varying legal definitions it different states.
I wouldn’t call this sexual assault because I don’t think it would meet the legal definition in any of them (except maybe California).
Sure, he’s a piece of shit, and arguably he coerced or pressured her into sex. But she agreed to it and says as much herself.
You could definitely say he abused her, or even sexually abused her but I wouldn’t say he sexually assaulted her, because it probably would not be possible to charge him with that anywhere in the country.
I understand that definition of “enthusiastic consent” but think it’s not very workable. Theoretically both sides should be enthusiastic, but in reality, how are you going to have some sort of definition of “misconduct” where one person asks another to have sex, that person says yes and then later says “oh, I didn’t really want to do it, so it was an assault”. Because the idea that two people are having sex and one person is not that into it that day/night seems like a really common occurrence, even within a relatively normal relationship.
I think it also is asking people to be mind readers. I’m not sure how a person is expected to know what the other person is thinking. At some point you have to expect people to have agency, and outside of a physical threat, being really fucked up, or in an abusive situation, people have to take responsibility for being clear about their desires and what they are ok with and state those clearly.
It’s why I’d say that Aziz Ansari is kind of a douche bag, but he’s not a sexual predator. He pressed up until the point she said a firm no, and then backed off. If we settle on some kind of abuse standard that requires you to examine your feelings to determine if you were assaulted, or worse, anticipate the other persons emotional state to know if you have committed a crime, I just don’t think it is workable or a particularly useful definition.