The only thing that I would add is that you do it tactfully. That is, think about the other guy. He could be getting all excited about finally getting to meet someone, especially if he's closeted, and maybe even growing to like "you", or who he thinks you are. It's tough enough to meet someone when you're either straight, or fully out, but for someone who's closeted, for whatever reason, they're typically apprehensive, on some level, to try meeting people. So, this guy goes, works up the nerve to try it, and has this pulled on him. You can confess, in hopes of making it work, or you can "break up" with confessing, "look, you're a great guy, but I don't think it's gonna work out, because I wasn't truthful about who I am". But you CANNOT just drop this guy with no information, leaving him wondering what HE did "wrong", and even more uptight about trying to meet someone in the future.

BTW, I agree with njqt, do NOT use fake pix!!! That just sucks on SO many levels.