According to the season 3 episode Destiny Cardassians view irritation and snark, when directed at a certain individual, as a sign of sexual attraction/interest towards that individual
I have always believed that Dukat, with his twisted mind, interpreted Kira's continuous obvious irritation and snark toward him as her flirting with him even though she wasnt Cardassian and didnt intend it that way. In the episode Civil Defense we have Garak, rather wonderfully, revealing that Dukats posturing and arrogant assertians that he will get them out of the hopeless sistuation are actually his attempt to flirt with and impress Major Kira.
So he did attempt to flirt with her the Cardassian way so its not too impossible to think that he was repsonding to what his twisted mind percieved as her flirting with him in the Cardassian way.
Of course in later seasons he just blatantly makes passes at her and his twisted need to be loved by Bajorans becomes obvious. I get the feeling this post didnt make much sense its mostly ramblings oh well...