Philosophical quandary

Dear Tee Shirt Girl,

I am faced with a deep philosophical quandary-
Specifically, at what point does one officially become a dirty old man?
My wife once said to me (when I was much younger and giving her a more than admiring look. Which I think is okay, since she is my wife. :-)
Anyway, she said, ‘You are a dirty old man.’
To which I had to respond with, ‘Excuse me! I am a dirty Young man. Someday, I hope to be a dirty old man!’

So, is it a matter of how old I am? Or is it relative to how old the woman is?
It is somewhat permissible for a thirty-year-old guy to ogle(to look at amorously, flirtatiously, or impertinently.) a twenty-five-year-old gal. And it’s okay for him to ogle a thirty-five-year-old gal. But a forty-five-year-old guy should not be ogling a twenty-five-year-old gal.

I think perhaps I need to poll a number of women and find out what they consider a D.O.M. to be.

That way, I will know when can I start wearing a tee shirt that says-

IT’S OFFICIAL!
I AM NOW A DIRTY OLD MAN!
(WOHOO!!) OR (YIPEE!!)

(And I sincerely hope that one of you is Bolera enough to say, ‘Oh Warty! You are much too young to wear that tee shirt!’)