I'm going to respectfully disagree with the above analysis, except on some of the pacing notes, but the dialogue felt very believable and effective.
As an intersex person, I've been though many of the same things as my trans friends, and I absolutely knew a guy like this in high school. The way the dialogue played out vibed very real to me, and that kind of scene is something I've seen my trans friends go through too.
People who have these...prejudices...often speak in what could be described as "word vomit".