Characterization

I’m reading JAG fics right now since I recently have been watching the early episodes of the show (since it is what NCIS is spun off of) and it got me wondering about something.

When someone has a nickname, or if two characters were to call each other by their last names, would having a relationship change them calling each other that? 

For example, Would Jack O’Neill start calling Sam ‘Sam’ all the time if they were together, or would he still call her Carter?  Now I’m pretty sure Sam would call Jack, Jack (although a few slip ups to Sir would probably happen).  She’s called him that before (again, when not ‘sir).  Sir would be awkward to call one’s boyfriend.

What brought this up was JAG fic where Harm starts calling Mac Sarah all the time.  Now I can see a few times since it is her name.  But the majority of the time?  I think he would still call her Mac. 

I guess its all in how we view the characters, or view how that type of relationship would work. 

I just couldn’t see someone stop using a nickname because they become lovers.  Now, in Sam’s case I could see a change in address because she calls Jack ‘Sir’ and by his title alot due to them being the same chain of command for most of their relationship.   And I think Kate would probably alternate between calling Tony by his name or DiNozzo.  He’d probably still sneak a Katie in every once and awhile.  But its not a huge change from what they do now.

I guess its mostly just a personal quirk that I don’t see having people change what they call people because they switch from being friends to dating/married.    Sometimes I see them using personal nicknames, like someone calling someone named John, Jay or something of that nature.  I’m not big on the whole pet names though.