I don't know
XFCrowman well enough to make any kind of guess about how anyone reads him, but I do have a question relating to this node.
If virtually the same thing had happened with a woman who you knew casually, who had misread your signals, let's say, would you be questioning yourself along similar lines? Why worry about a simple (if somewhat embarassing, for you both, I expect) mistake in reading each other's interests?
Yes, this might have been awkward for you and for him, but why does it leave you questioning yourself on how you are coming across? I would be willing to take at face value that the guy in question read your openness as an invitation, in part because it's relatively rare to see whole-hearted acceptance coming from those who identify themselves very strongly as "straight" (and those often as not, are the ones concealing their own conflicted attractions to the same sex, in my limited experience.)
Being a sweet, open sort of guy may leave you with the impression that other people too might be reading you as gay, and maybe some are. But does their misunderstanding change your inner sense of who you find attractive? And would you really feel good about changing the way you act, just to "prove" to some faceless group of "other people" that you are "straight"?
Just a few thoughts on the subject.