For fun, of course -- or out of personal affinity. When we're taling AIs, rather than programmes, one can imagine all sorts of personality quirks and different preferences... perhaps of a diversity even greater than the range among humans.While I really liked the story update, I'm not a fan of Eve and Legacy being husband and wife. Why would combat AI have genders at all?
But... I also don't necessarily trust their description of their relationship... or anything about them. There's no reason to take anything they say at face value... and, indeed, plenty of reason not to. Which is great! I enjoy the fact that Panda's narrative has a logic to it, as well as a great deal of unpredictability and uncertainty.