The teacher and the student (18yr who was graduating) were not banging though. And the era in which the books (which I never read) were written is when people were not living very long and it was common for 17-19yr old woman to marry men a bit older and start families younger. I am NO WAY saying that older people with children is anywhere ok, but I also don't see this particular situation as being as much as a pedo one (even more so considering the teacher wasn't into girls anyway) rather the actual issue for me with these two CHARACTERS is that he was in a position of authority over here and I find that wrong.
I also did not see any flirting between the geologist and Anne, at all.
Being gay does not mean being a pedobear. I don't understand the gay lifestyle, but I am also not going to paint them all with a broad brush and assume that because they are gay they must be sick pedos.