When do you think its okay?

I spoke to my mom today, she was clearly not in a good mood. Turns out something is up with my sister.
Its not something serious to most parents, its life to most, but to my parents it is not acceptable at this age.
My sister is 14 and she has a possible boyfriend.
My parents have NEVER allowed us to date before 18. But you know what happens when your NOT allowed, you do it anyways and you do it secretly.
And doing things in secret causes more problems, you start lying and start doing things even more cause you think no one knows.
See my parents had it SO easy with me.
I was always good. Never misbehaved. Did things "correctly" whatever that means and just overall never gave them a headache.
Of course on the other hand i was a difficult CHILD and i have a temper, whether people see it or not I do have a temper, it comes from my dad.
Either way, the years that "matter" those were the ones i was "good"
That doesn't mean i didn't "like" boys at 13,14,15... I did, i was just TOO shy and i didn't consider myself attractive till i was 16 anyways.
When i was 16 I went to boarding school.
I LOVED it there it was best times ever.
I had a crush on a boy, and he didn't like me back. which was fine.
I never thought of dating anyone throughout highschool anyways. I was a nerd and got striaght A's.
But then out of no where the "hottest, popular" guy told all my friends he liked me.
He was a man whore, He dated all the girls and thought he was the "ish" .
When i found out he told my friends GF to tell me i told her " tell him NOT IN A MILLION YEARS"
Yup. i loathed him
My best friend had been in love with him since 7th grade.
I knew his name "j"
I have heard of him since i was in 7th grade also.
Needless to say he tried REALLY hard to just talk to me. He waiting outside of my band practice, my bell practice, my choir practice.. he waited just to walk with me to my dorm room.
Did I mention he was the Head dean and pastors kid?
Yeah.
FInally i started to let my walls down after i read his journal.
How did i get his jorunal?
Well i was the english/spanish teachers assistant.
I helped him grade papers.
This was a boarding school that you also worked to help pay your own tution.
I had to "check" that everyone had certain amount of journal entries and give them points.
So his journal was next.
I was "should i... should i not..."
I did, I couldn't help myself, I wanted to see if he talked about me in his journal.
And he did.
He said how i was different from all the other girls, and that we would want to marry me.
He said he was SHY for the first time ever around a girl and that I made him feel like a little school boy.
After that I started to give him a chance.
Long story short, we never dated, but he was my first kiss.
Once a bad boy always a bad boy? Well in his case it was true.
He ended up going to college, * he was a year older than me*
and he got his GF pregnant.
Yeah. I escaped that one.
Ill tell my love story with my husband at another time.
The point it is my sister is going through HELL with my parents once they found out she was holding hands with this boy.
My dad was like " I CAN'T handle seeing my little girl holding hands with a boy"

I told my parents they need to chill and realize my sister is NOT ME.
A lot of people except a lot from her cause of me.
My mom thinks if she has a BOYFRIEND now she will NEVER finish college and will get married and not get a degree.
Its her own fears.
She had 1 more year of dental school when she got married then pregnant with me, and moved to america and never finished school.
That is her biggest fear, and i UNDERSTAND that.
But i told her MOST highschool loves, not ALL usually end .
I told her to relax.
They told her she couldn't date till she was 18.
Somehow i managed to lower the age to 16 today.
They need a chill pill and trust their parenting.
See his parents have been secretly taking them to movies and my sister has been lying to them
I told them they can't be mad, cause she is going to lie to them cause she can't be open about those things.
What do you think?
What has been your experience?