And they'll tell two friends, and so on, and so on..... lol
I think there's something to male shame about it. I mean, women getting breast enlargement has become a part of our culture that it's no big deal. I'll venture to guess there was a time when it wasn't talked about and done 'in the closet'.
I think it may have something to do with how the penis is attached to a man's value as a man. It's programmed culturally. So to tell people you are growing your unit it implies you aren't man enough already. I know this is erroneous thinking on society's part but I believe it exists. The other thing is, we are doing something which society claims as 'impossible' so it sets us outside the bubble of 'norm'.
Last year I wouldn't say anything to anyone, but this year I've been working on transparency and putting my authentic self out there, that I no longer give a shit what people think about me. I'm perfectly fine the way I am and have no problem standing up and owning myself and the things I do. It's my life and people have a problem with it, it's their problem.
I think if you present it without any 'shame' and no need to defend yourself and hold the mindset it's no big deal, then it will become no big deal to those you tell.