*crawls out of hole*
I don't post much here or anywhere else for that matter. I'm usually content to just post my crap and disappear. It seemed that it might be important to say a couple things, though, since you're having trouble here. I'm probably only going to be able to reinforce things that have been said, but since I've been around this block before I'll try anyway.
First of all, to continue what Ahastar said. You're on a website mainly about very large reptilian feet. Being bisexual doesn't seem like a big concern in comparison. Not that anything's wrong with the latter, either, but you never know who's going to give you the funny look.
I'm lucky, I suppose, in that I've had the good fortune to have at least one friend who couldn't give a crap. It was pure horror for me when I saw him open the folder of porns. (Hey kids, don't put your fetish artwork in a folder called "Stuff" in your My Documents folder and then let your friends use your computer. For future reference.) The fact that life has continued pretty much unaffected from that point proves that many people and real friends might not care as much as you think.
As for personally, as in your own feelings, I wouldn't worry about it. Sexual orientation and related goods are pretty unimportant in the grand scheme, it seems to me. Being bisexual is not a mental illness nor can it hurt you. I have obsessive compulsive disorder, which has led me to far more trouble and embarassment than any inclination towards large (and often male) dragon feet.
So buck up and all that, and hope you feel better about it. Time to slink away.