Sisko always claimed that he was not attracted to Jadzia but he slept with the mirror Dax.
Do you think this proves he really was attracted to her?
IMO I think it does and I would have done the same thing. You get to sleep with Dax but have none of the awkward consequences.
Well, what are you actually asking? Was Sisko attracted to Jadzia... or was Sisko attracted to Dax
I thought he found Jadzia an attractive woman when he first met her, which made it weird for him at first since she was Dax and talked to him as if she was Curzon... But he quickly started thinking of her as DAX, his old friend/mentor (as seen in the nickname "Old Man"), and this completely erased any sexual feelings he might have had for this woman if she had not been Dax.
In the MU, since this version of Jadzia Dax was so different, maybe he didn't have such a problem.
On the other hand, if you think he was in fact attracted to DAX all this time... Well, that's an interesting new perspective on things.