I’m kicking myself right now. An old friend from the East Coast got in touch with me about setting up her brother-in-law with an eligible and attractive single Jewish woman here in Seattle, and did I know of such a person. It turns out I sure do but then I blundered. I told my friend that the woman I have in mind is shomer Shabbat. She observes the Sabbath. Immediately my friend, the other go-between, was wary. The guy in question is Reform, not observant at all. I’m very annoyed at myself because I know perfectly well that in Jewish dating — and let all Jewish singles hear this well — this is the kind of thing — like being a Republican — that you have to keep secret in dating till at least the third date. 

My perspective is that unless you are talking about an exclusively religious dating scene — and this is not the context here — then there are some things, some beliefs and practices, that can only be evaluated in a person once you know him, or in this case her, personally.  You do not have to lay all your cards on the table on a first date. You should not do so.