Some commenters seemingly don't understand the position Endou is in.
We've seen that Teiai can get away with some pretty nasty stuff if they want to, and we know that the chairman and his son are both nutcases. In that yakuza-like organization headed by sadists, Kurosaki is #2. If Hyodou can make a grown ass man kneel down on a blazing hot iron table without any repercussions, it's not farfetched to believe that Kurosaki could do similarly outlandish things. In fact, Endou has been consistently assuming the worst of Kurosakis intentions for a while now. From an in-universe perspective, Endou is still very paranoid, but not entirely without reason. Kurosaki could hardly be in the position he is if he didn't approve of certain practices like the labor camps or the deathgames.
You could question whether the author could have chosen a different way to depict Endous fear and the ensuing misunderstandings - but frankly, why? It's not like Fukumoto *actually* made Kurosaki into a gay rapist for laughs. And in an age where society becomes increasingly more tolerant of homosexuality and more aware of powerdynamics, Fukumoto showing that even men can fear to be abused is downright progressive.
I mean, it's not like it doesn't happen. The catholic church faces critism for a reason, and everyone knows the ancient greeks liked it up the bum and had slaves. I'd rather not we pretend that homosexuals aren't people who can be just as terrible - or good - as everyone else.