@smashman42 i mean right in this very chapter he says "naturally. i told you i wont feel that way towards my students"
that pretty much sums up everything his character has been built to be, it has nothing to do with sexuality.
If theres a big reveal of ..."I didnt touch you because im gay, not because im a good teacher", that would be an awful conclusion. he wont touch them because he's a decent human being, not because he literally cant get hard to them.
thats on the same level of just saying "oh surprise! plot twist! i wasnt interested in you girls because i have erectile dysfunction!" its just lame imo
also i dont at all beleive highschool girls are some mythical force of sexual aura that adults cant help but want to bang. its very easy to not get tempted, everything that happens in a manga involving them is obviously for the sake of a story, and this is coming from a 19 year old.