hi, i'm a 16 year old guy who has been in a relationship since
sec2. my current gf is my first and we've been together for about
3-4 years now. from my own personal experience, there are two main
groups of ppl going to relationships. one is those that go for lust
without thinking of anything. the other group is those who are
serious in love. i have many friends who, unlike what most older
adults think, stay in their relationships for many many years
without a major incident. however, there is the other group who
f**k and throw kind. these go for lust only. the approx ratio of
those serious to non serious, in my class at least, works out to be
50:50.
when parents feel that BGRs at this age is not good at all, it is
not totally true. speaking about the ppl who are serious(those who
aren't, obviously isnt a good thing), BGRs that affect studies are
rare to find. in fact, among my friends who have relationships,
their results actually improved steadily, as both encourage each
other. in my case, i can safely say that my gf helped me alot in
studies as well. when i was down, she would encourage me to study
and taught me maths and science. if she was down, i would do the
same back to her. for these ppl, BGR actually teach the guys how to
act more maturely and more gentlemanly. girl our age tend to be
more...cultured, and thus to please them, we make small sacrifices
like dressing more neatly and shaving cleanly. 
however, i have got nothing to say about ppl who don't treat
relationships seriously. i don't have much respect for these ppl
who jump girls or guys after only a week or two.