Or leave off the "no good reasons" part, because "I don't like it" is a perfectly good reasons.

I think it's along the same lines as not wanting to be called a nickname - you don't need a reason, it's a preference.

Full disclosure - I nickname people a lot, and have been asked once or twice to just go back to calling someone by their name.

I snapped at a friend who greeted me at a party with "Steffie!"* But, I mean, I'd known that person for several years, and NEVER in my life have I ever EVER used that name, and I really hate it. (I think my mom might call me that once in a while, but she also calls me Dolly and other variations on Dolly [Dollmeister; Dolly Lama]; at this point, they don't register with me if it's coming from my mom.) But I really shouldn't have snapped at my friend; I definitely could have handled it better.

*(Despite hating it when anyone calls me Steffie, I have zero problem with Teppy. But only you guys call me that. And I love it.)

I've had people call me "Toddy" (shudder). We have a woman in my office who had the habit of giving people nicknames, mostly with little relation to their actual names, and insisted on using those rather than their actual names. Or even a nickname based on their actual name. She liked to warble out, at full volume, her nickname for anyone ... I suspect that at least one person left because they hated that nickname so much.

I've had people call me "Toddy" (shudder).

I think "Toddy" is cute, but more because I associate it with Robert Preston's character in Victor/Victoria than because I think it suits you!

And I've never allowed anyone to call me "Mellie" even though that's one of Melanie's nicknames in Gone With the Wind.

And of course, if looks could kill, I'd have a couple of dead coworkers who thought it would be funny to jokingly call me "Melania".

People have tried to call me Sally. This has not ended well for them.

I think "hey, do you mind not calling me that? I don't really care for it" would be better than a deflection that might be understood at playing along with the joke.

I said "am not a lady" and I think that took care of it.

Sorry for having a little freak-out there.

Unfortunately, there are any number of people who think it's cute, or amusing, or just OK for them to rename people regardless of what the person thinks, as in the woman in my office.

Sorry for having a little freak-out there.

It wasn't a freak-out, you were talking to people you knew would listen. It sounds like the direct approach worked.

Here, watch a baby eat ice cream for the first time. [link]

Unfortunately, there are any number of people who think it's cute, or amusing, or just OK for them to rename people regardless of what the person thinks, as in the woman in my office.

As a serial nick-namer, allow me to say Not OK, Nicknamers Who Don't Take Other People's Preferences Into Account!