It just occurred to me that this whole label thing doesn't really make sense in this case. To consider it from another angle, try to answer this question:

Can a punk rocker like a country & western song?
If so, is he still considered 100% punk if he likes this one song? or if he heard it and liked it just the one time?

The answer is, of course he's still 100% punk, but the greater answer is: musical preference does not define you absolutely. By the same token, I don't think the things we wind up doing sexually necessarily define our orientation. Just because I've kissed/made out with guys during spin-the-bottle or truth-or-dare and whacked off a few times watching porn with my roommate, doesn't mean I want to pirsue a romantic relationship with a man.

In situations like the subject of this thread, I think it would be wiser to evaluate someone based not on what they do, (or have done once), and look more at how they feel, and what they want.

Does that make sense?