Nobody I've been in a relationship with has ever suggested it to me. Instead, I've made - what was in my experience and opinion - the mistake of letting them know that I had bipolar disorder. Maybe it was that I let them know too soon (a few months in), but every time I found myself getting kind of "beaten over the head" with this fact when it seemed to suit the person I was in a relationship with. It typically came up during arguments or disagreements (where it had no bearing) as a way to disqualify an opinion or behavior the other party disagreed with or didn't like. Many times it took the form of a heat of the moment type cheap shot.

How would I feel if someone figured it out and brought the subject up before I did? Probably relieved, as it takes away two problems surrounding the subject for me in a relationship: the uncertainty of how to bring it up and how the person will then react to it, and the discomfiting feeling of keeping part of myself somehow "hidden" from them until I do.