Maybe it's what they do to keep the proper distance.  I have a 3 letter name as well and I get the same treatment.

If you were seeing 3 to 5 people a day, and working a few days of work each week, and answering emails with a million different names and board handles, phone calls, and so forth do you think you could keep it straight?  Then unless you are seeing them on a weekly basis, but more once a month or every few months, do you really think they can remember? These ladies are multitasking enough as it is, I am surprised half of them keep it together as much as they do.

How many  mongers remember your wives birthdays? Or is that a defense mechanism too?

I think your reading too much into this.  It could just be habit or have no meaning behind it at all.  Just relax and enjoy the fun with her