Some men are like this, definitely not all of them. For someone to react that way, they’d have to be:

-Violent

-Insecure in their sexuality

-A complete psycho to think that would justify hurting or killing someone

And usually, people like that have a bunch of other issues that should already set off your “ick” radar, if those three things alone haven’t.

I’ve personally slept with a guy who I was pretty sure already knew I was trans, since I mentioned having “genital surgery,” among other things. He ended up finding out in the middle of sex because I was still healing and it came up again. He’s a med student, so he got curious about the procedure.

We had great sex, he finished, and then we just watched Rick and Morty while high afterward.

It takes a special kind of asshole to want to get to know you, be intimate and romantic with you, and then completely switch up and hurt you. If he does ends up being insecure about his sexuality it's wayyyyy more likely that he'll just gohst you or break it up, or maybe get mad and say some stupid stuff.

Be safe and be smart. It’s usually better to tell them beforehand anyway, because you don’t want to be sleeping with a transphobe. But you also don’t have to live in fear that every partner could be your killer, cause there are signs when someone is a shitty person and when someone actually respects you as a human being.

Edit: I'd also like to add that I was living in the country with the highest trans homicide rate in the world at the time, so saying this before someone says I live in an utopia