Dating landmines - talking about "the past"

I got into a discussion with a female friend about the phrase "dating" versus "seeing someone". My take is there is a difference - if you''ve "dated" someone, you've had sex with them. If you were "seeing someone" then you haven't. She thought I was crazy.

Then I went on jury duty and we were handed a portion of California law that actually defined "dating" as one that included a "sexual relationship"....sweet - I was right (seriously laughed when I saw that).

BUT - if you're now starting something with a new person and past lovers or bf/gf's come up - how do you frame that?

This person I've started dating (yep - my definition) keeps telling me about some of the guys she's "dated" and I keep telling her that I don't really need a chronicling of all the guys she's slept with...to which she keeps telling me she never slept with them. So I've asked her to make the distinction between "dating" and "seeing someone" or I'll start to think she's slept with everyone in the Northern Hemisphere. She thinks I'm taking this too seriously but I really don't need to know who and how many guys she's been with - really don't want to know.

Thoughts?