OOC: Kiki, Crowley and Aziraphale
Contrary to appearances, Kiki is not immune to Crowley's influences. The reason it is taking longer for Crowley to affect Kiki is in part due to a innate magical protection she has (witch heritage), but more so than that, her own good-nature and an upbringing in which her upstanding parents instilled her with all sorts of wholesome, boring virtues and values like forgiveness, tact, politeness, truthfulness, good manners, loyalty, friendship, honesty, etc. etc. etc. What began as simple curiosity about Aziraphale's pal - and Kiki would say something like, "any friend of Aziraphale's is a friend of mine," - is slowly turning into a sort of morbid fascination bordering on obsession (non-sexual, but if Harry wants to get jealous, yay for more drama!). Kiki is certainly unaware of the effect of Crowley's nature on her, and Crowley himself may not be cognizant - he is affecting Kiki whether or not he is specifically out to do so.
Kiki has this odd notion that Crowley, in his own way, likes her, and she keeps thinking that someday she'll manage to crack a genuine smile out of him (Keeks, keep dreamin'). Thus her endless cheerfulness around him - at least, when they first met. Crowley's influence is making Kiki a bit moody. As the first symptoms of Crowley's influence are only just starting to appear, it is likely that Crowley and Aziraphale have noticed nothing unusual - after all, every human (female) gets moody, right? And they've had their own issues to sort out. Recently, she's found herself getting depressed, but she attributes it to stress or Kitty Pryde's death and memorial service. She's still very cheerful, helpful, and good to the point of being annoying - but not all the time. She's becoming more withdrawn and tired, but has no notion that it could be caused by anything except her own issues. As she considers Crowley her friend, she's not about to leave off visiting and/or being annoyingly cheerful to him - after all, she finds him very intriguing and fascinating: he's very charismatic in spite of being Mr. Grumpypants, and she's so curious/fascinated, she can't seem to leave Crowley alone. Obviously, this does nothing to help her situation.