Whether it's right or not, the reality is that many if not most heterosexual women would likely object to having sex with a gay man, even if the man told them upfront and even if they expected to use safe sex practices.
Ironically, as was evidenced in this episode, many of those same heterosexual women would have less of a/no problem having sex with a someone they knew or assumed to be a promiscuous heterosexual man, as long as they were going to use safe sex practices.
(Note, I am not equating "gay" with "promiscuous." However, that is how many heterosexual women would assess the comparative risks, whether their beliefs were based on proven facts or not.)
IMO, Kwame knew and took advantage of the above-described disparity. That said, his date had made an erroneous presumption about his sexual orientation, but that was likely because Kwame misrepresented himself on the dating app.
And finally, there were racial and cultural issues at play too. I doubt Kwame would've tried to pull what he did on a random Black woman. He probably specifically chose a White woman because of a whole other set of assumptions and stereotypes about dating and having relationships with Black versus White women.
Now Kwame's date admitted she was "into" Black men and had clearly sexually fetishized him before she even met him. That might just be one of the things one might encounter in interracial hookups with people you don't know, regardless of their sexual orientation. I still think she was entitled to be told beforehand that she was being used as an experiment by Kwame.