Thanks everyone. I'm really feeling much better now. DH and I talked and he helped me get a grip.
So here's where it is - and don't get mad at me.
She's my friend. I don't want to change that. I'm a humongous flirt - guys, girls, doesn't matter - so this is somewhat my own doing. I have absolutely no problem with the fact that she's bi so that's not an issue. I'm not going to be *****y or mean to her because I think that invalidates her feelings - and like I said, she's my friend. Finally, both husbands know about this and both are just fine.
So I'm going to do nothing.
She knows I'm married and she knows I'm not betraying that ever, so it's a non-issue at this point. DH even got me laughing about it, so that's good. Really, I just think I was so completely caught off guard by the whole thing that I couldn't even think straight (no pun

) So all is well
