why it is unethical to ask for a woman age?

I don't really think it is a question of ethics but a question of vanity. It is a question of wanting immortality (LOL) or remaining young as being young presupposes being attractive still. It is a wrong notion actually since I believe that being attractive comes from the totality of a person, not just the physical appearance.

maybe coz girl is too shy and not that comfortable about telling there age. specaily if they are older than u

Well, asking anyone their age is personal if it's just idle curiosity. That goes for men as well as women. But, the idea that it's taboo just towards women comes from an outdated idea that women lose something - desirability, interest, whatever- when they age. So there's a sense that asking a woman her age means she's either required to lie or reveal the 'shameful' secret of how old she really is. Which is complete crap, because imagine that kind of attitude towards a man. Not going to happen.

hi. I am on my way to meet my husband and am logging into mylot.com it is addictive isn't it? Well to answer your question, I have never lied about my age anywhere or to any one and I don't mind when somebody asks my age. And I seriously don't understand what the fuss is all about.