It also must have been uncomfortable for Sisko to mate with mirror universe Jadzia, as implied in "Through the Looking Glass".
That's actually one of my biggest pet-peeves with this episodes and the show in general. I don't get why the writers thought it would be okay for them just to have sex without at least addressing the fact that it must be really uncomfortable for Sisko. Drives me crazy that they are presenting it as such a casual thing.
Maybe they didn't address it because it wasn't
uncomfortable for Sisko to have sex with mirror Jadzia. Why would he be uncomfortable? He was undercover, and she's not