Hi, Caren

I personally think that a person should earn the right to know that you are Bipolar. What I mean by that is that the person should have the opportunity to get to know you as a person, your strengths and perhaps your weaknesses but basically get to know you for who you are. To see if you click and if the relationship is one that will have some potential for longevity. I just think that too many people have no idea what Bipolar is.....and that may lead to an early stigmatization that wouldn't allow the person the opportunity to see you for who you really rather than seeing you as having a mental illness. Once this guy is able to see you for YOU without being clouded by a misperception he will most likely take an interest in learning more about Bipolar and what that means and how it may affect your relationship in the long run.
The time to tell him will be clear to you. So perhaps a second date may be too soon.....I think that you should allow yourselves some time to get to know one another before sharing your Bipolarity to him. Like a person who has ADD and is properly medicated may not disclose that information right away, I think that you should wait a bit and give each of you time to see one another without any misjudgements getting in the way.
Hope this helps you out a little bit.
~ Goody