I know I've rewatched DS9 too many times: either I am noticing things that are very subtle, or I am imagining things that aren't really there. In this case, I keep seeing parts of the script where the real life romance between Visitor and Siddig was referenced into the script--or more exactly, where an awareness of their romance adds depth to their interaction. Of course, there is the scene in which they make out in Infatuation--eerily not sexy. At the beginning of In The Cards, they look like a bickering, old couple. Bashir also checks up on Kira's relationships on a number of occasions, like when she carries the O'Brien's kid or the night after Kira's date with MU Bareil, even betraying some jealousy. If that was the case, it does add a little fun to the scripts after repeated viewing.