Wo-man
You: God became man... [or similar provocative lead-in]
She: No! God became human!
You: But 'man' includes both men and women.
She: No it doesn't!
You: Well, look, you don't have any difficulty with me refering to you as a woman?
She: No, woman is a good word. [Yes, feminists really like it. Ah, how they prepare their downfall!]
You: And I'm allowed to refer to myself as a man, right.
She: Right.
You: But don't you know that the word 'woman' is in fact a qualification of the word 'man'. A woman is a wo-man.
She: Huh?
You: Yes, for English, because man basically means 'human being', there can be a male man or a female man. When we need to mark it explicitly as female, we say 'wo-man'. The wo- bit originally meant wife: a wo-man was a man who could be a wife! Anyway, my point is simply that when you use the word 'woman' you are using the word 'man' in its generic sense, which you claim it cannot have.
She: Eh, I'll have to think about that...
You: [aside] phew!