Considering that I would most likely find out on the 1st 2nd or 3rd date, I would not be angry about the deception. If it was something that was going on for years I could totally understand freaking out, but not after a few weeks.
In regards to what I would do, I'd probably give it a shot (assuming this is some spectacular soulmate whatever type like the op said). Most likely, it would end eventually, but who knows, it could be interesting. If nothing else, it would be an amusing anecdote to tell, and it would give me some idea as to whether or not gay/bi whatever relationships would be viable for me.
Frankly, I would think the most unusual aspect of the relationship would be that we would have so much in common, and not the fact that it is actually just another guy. Most men and women have virtually nothing in common ... at least that has been my experience (and it still is with my current relationship). Being romantically invovled with someone that shares my interests would be quite refreshing to the point that it would offset any odd feelings I would have about the homosexuality.
