The writing just seemed to be so immature on this topic.but Odo's increasing infatuation with Kira (and her eventual reciprocation of it) was just one I was never that fond of.
The female changeling has sex with Odo, then she goes "so this is what solids do to feel closer to each other, but it pales compared to the great link"
Odo just looks confused, so the female changeling says "oh I see, you want to experience this with Kira" and he's basically agreeing.
Odo really really wants to go to the great link, but he really really wants to have sex with Kira.
Kira says yes, and now he's torn on which group to be loyal to, and in the end decides pro-Kira.
Can you imagine if she had rejected him? The whole Alpha Quadrant would have been toast, because Odo would have left DS9 and rejoined the great link to battle against the solids, and there would have been no one to convince the female shapeshifter to give the solids a chance.

As for Worf and Jadzia, that so reminds me of Beauty and the Beast. It's like the Disney cartoon, but in Trek mode.