1)To answer objectively,
Your question ain't right or wrong.
It is catergorized as 'unsafe questions'
Unsafe questions are dbl edged. It could lead to humour or tension.
It all depends how well you know the person you're speaking
to.
You obviously don't ask a girl on the street what's her Cup size do
you?
But if you've a gal buddy, i'm sure she'd take your question
lightly and answer you.
2i) Age is not a secret. But everyone have the right to protect
themselves. of their personal identity/details.
2ii) Yes, question about age to some women is as
sensitive/offensive
as if you're asking about her panties she wear
OR her makeup don't look good on her.
OR how are her parents (her parents died)
3) If she didn't want to answer you, let it go.
She is under NO OBLIGATION to lie to you. Hence, she's under ZERO
OBLIGATION to serve you and entertain you as well. In F&B
standards, whenever a staff is unhappy serving a guest, he/she is
allowed NOT to serve him at all.
Personal note: you're speaking as if being Customer is big
fark.
You should quit the habit.