What do I do?

Here's a head scratcher for you. Elliott has been in school with Kenneth since JK. Junior Kindergarten starts at 5 so they've been friends for 9 years. For 9 years they've been to each other's birthdays and countless playdates. On top of it, Kenneth has a younger brother named Kevan (their typo not mine) who's the same age as Henry so double that number.

The problem is Kenneth's mother. We call and speak to each other to arrange these dates. Every time we talk she calls me Kim. We've talked about 3 times a month for over 9 years and she thinks my name is Kim. She's a lovely woman. Always smiling, sweet, happy and she thinks my name is Kim. It's partly my fault. I should have told her my name is Karen right from the start. But now it's been too long. I can't tell her now. I'll humiliate her, won't I?

But then I think about her talking to another parent about me:

Raquel (Kenneth's mum): So I was talking to Elliott's mother Kim the other day and...

Other mother: Elliott's mum? You mean Karen?

Raquel: No, I mean Kim. I've known her for 9 years. 

OM: I'm positive her name is Karen.

Raquel: It can't be. I've been calling her Kim for years... surely she would have said something.

OM: I don't know what to tell you. She must be messing with your head. Her name is definitely Karen.

Raquel: That bitch.

See? So now I'm a bitch for trying to spare her feelings. I don't know what to do here. Little help?

kxx