Any of us that have taught children up through high school can see that a lot of the boys are very touchy with each other. And I have seen so many young guys in their 20s hugging and being all touchy feely in bars. I have even seen old men do the touchy stuff in public.
Additionally, the boy students almost all refuse to do any pair work or conversation activities with the girls unless you directly point to a boy and a girl and force them into the same group.
I know some could say that it is a "cultural thing", but is it an "all the men actually gay cultural thing"??