1. It happened many times. Age gap 5 to 10 years is not a
lot.
Hope it's not from the same school, and hope the girl is older.
If you're talking about sec sch, it's a little hard to develop
such r/s because girls at their age think with heart and dunno how
to think properly. If you say JC/Poly, chances is very low also
because institution engage experience person to teach, same age gap
but difference a lot. Uni, I think not possible cos of the busy
syllabus.
2. Some is both teacher and student mutual infatuation.
While some teacher die die also don't want
smash signboard~ While some is student die die want go steady with
teacher.
Depend on the situation la.
3. Nothing is wrong, but it stain the professionalism of
teaching of that educator. It's like smashing your signboard.
Unless you are talking about private tutors which aren't bounded by
institutions, then it's easier to go from there. If you're lecturer
from NUS and got bgr with student, say bye bye to your
signboard!
4. Anything above 16 is ok. Anything below 16 is not okay.