sunstallion said:
you don't know this guy. he's a sex expert, a relationship expert, and is excellent in psychology. that's why he said he won't bother to waste his time if his interest is straight because he would have no chance.
Does that mean anyone gay/bi would be almost automatically "his" due to his amazing expertise in sex, relationships, and psychology? I'm sorry, but I have a hard time believing this.
Anyhow. Why not take three scraps of paper, write "gay," "straight," and "bi" on them, and simply draw lots if this is really all your friend needs to know about the guy he's interested in? While this may not be such a mysteriously charged oracle, it should work much better than a tarot reading which will give you way too much room for interpretation anyway...
If the oracle says the guy is bi, you can always try and determine the percentage to which he's gay/straight. Your friend may not wish to waste his time on a guy who is only 5% gay (which WOULD make him bi at least by calculation, if not by identification), either...