16-17 are the last years of your typical irrational teenager I think. Personally I was pretty decent in my teens and didn't cause my parents much stress.
Not for me, I think I still irritate my parents in my selfish ways, theres just less of it now and as they are used to years of trouble when my brothers where at home they pick up on little things that I do which sends me into proper paddy-wack mode.
Also, is a long term relationship much different to marrage?
The only difference I see is the legal (and religious I guess) contract between you.